# Other Aquarium Forums > Equipment and Accessories >  DIY Chiller

## timebomb

Hi, folks,

One piece of equipment that has been discussed for years by planted tank hobbyist is the DIY Chiller. I've heard of many methods but none is really effective. The best way to cool a tank, as far as I know, is to use cooling fans. They are cheap but they have their limits. The very most they can do is bring the temperature down by 2 degrees Celsius from the ambient temperature. 

James Lim, my good friend and publisher of the Aqua Journal called me yesterday and he sounded excited over the phone. He told me he managed to rig up a DIY chiller for slightly more than Sing $200 and running costs are expected to cost only about Sing $5 a month. He also said it works better than the chillers sold in the market. He said his tank is so cold now there's condensation on the glass. Heck, I was sceptical at first. A normal chiller costs about a thousand dollars and running costs can be as high as $1 a day and I've yet to see a chiller causing condensation.

I woke up this morning to find an email from James. It came with an attached picture. Here it is:



Holy smoke!!! The tank looks really cold, don't you think? James said the thermometer reads 22 degrees C  :Shocked: 

I don't have the details yet but I will post them as soon as I find out exactly how James does it. By the way, James is also looking for people who are technically-inclined to help him on another DIY chiller project. He hopes Ronnie and Freddy can volunteer but he won't mind accepting anyone into the project so long as they are really keen on this. For his next project, James intend to work on a chiller that can chill large tanks of up to 1000 litres. It's going to be state-of-the-art and although costs can be quite high, it's still a lot cheaper than chillers sold in fish shops.

The thing about James besides being very well known for publishing the Aqua Journal, is that he's very creative and resourceful. Many years ago, he was the first Singaporean to come up with a DIY CO2 system that was so good, it was regarded as the Rolls Royce of all CO2 systems. Till this day, I'm still using that CO2 system. It works perfectly and the fine-tuning valve is so good I never have to tweak it.

Loh K L

----------


## stormhawk

That's one really cool tank. Condensation at that rate, and temperatures of 22degC? I think even coolwater killies can be considered as a possibility if one gets to know how James DIY-ed the chiller.

----------


## bad_boyz

Maybe james should patent his chiller. He should also hold a course on diy.

----------


## shortman

Hmm, I don't mind if it cost double so long that is a DIY and infact I love to DIY.

Anyone wanna team up to do this DIY?

Kwek Leong, would you mind please post more details soon, so I can start the chiller as soon as possible.

Luckly saw this message before going down to get the chiller from the shop near your place.  :Cool:  

Thanks you very much
Best Regards

----------


## Green Baron

That is really cool  :Laughing:  I have seen the effect of low temperature on mosses and many other plants in my office tank and am considering a chiller for home as well.

I like DIY. Count me in if I can help in anyway. I can volunteer my tank to test the DIY chiller :wink:

----------


## juilian75

Chk this out on DIY Chiller


http://www.aloha.net/~hqf/indexdonschiller.htm 1999 design

http://www.aloha.net/~hqf/indexjrosechiller.htm 2000 design

----------


## PohSan

I would like to have such a chiller also. KL, please give more information and let see what parts are needed. Maybe we can organise a mass DIY part ordering also.

Regards,
Ong Poh San

----------


## shortman

Let me do a count now we have the following

1. Gan C W
2. PohSan
3. A.Rashid
4. Shortman

We have count of 4 anyone else in game? :wink: 

JianYang, Ronnie and Freddy should I count you in?  :Smile:  

Best Regards

----------


## A.Rashid

DIY? count me in...

----------


## timebomb

It would be great if we can group together and do a bulk order on the parts needed but I would say, let me be the guinea pig first before we start buying anything. I don't want anyone to feel let down if the thing does not work out as expected.

Anyway, I went to James' house today and took some pictures of the DIY chiller. The tank's really cold. In fact, it was so cold James had to crank up the thermostat as the thermometer was going to go below 20 degrees C. James keeps some precious show Guppies in his tank and he wasn't sure how well they take to the low temperatures. 

The idea's pretty simple really but good ideas are always the simple ones. The DIY chiller involves using either a bar fridge or a small freezer. James is using a bar fridge which isn't as economical in space and less efficient than a freezer. James isn't really interested in building a chiller for small tanks so this is just an experimental DIY chiller as far as he's concerned. His next project, a DIY chiller that can cool large tanks of up to 1000 litres is the one he's really keen on. Anyway, here's a pic of the bar fridge. 



As you can see, there's an inlet and an outlet pipe. It feeds directly to and from an external cannister filter which if you look closely, is at the side of the bar fridge. Using a bar fridge to cool down a tank is an idea that has been proposed and discussed many times and those who have tried it say it won't work. James made some modifications to the old idea, one of which is to replace the rubber hoses with something that is more conductive to heat. James uses PVC hoses which are flexible enough to be coiled and conductive enough to make a difference. The other significant change is to immersed the coiled hose into a tub of water. Why so, you ask? Why can't we just simply leave the coiled hose inside the bar fridge? 

I'm no scientist so I can't give you the scientific reasons but this is how James explained it. Imagine if you leave a can of beer in your freezer. It will get very cold eventually but it will take some time. But if you put the can of beer in a tub of cold water filled with ice, it will chill much more quickly. The difference lies in the medium of heat transfer. With air, it's much slower. With water, the can of beer cools in double-quick time.

Here's a picture of the inside of the bar fridge:



As you can see, the space below the compartment where the tub of water stands is a waste of space. A freezer would be more space efficient as every cubic inch of the space inside can be used to hold a very long coiled hose. The compartment in the bar fridge James is using is so small the coiled hose can't be immersed fully. James also uses a small powerhead to circulate the water in the tub. Without this powerhead, there's a danger the water in the coiled hose can turn to ice. Circulating the water also ensures every inch of the hose is in contact with the cold water. Besides this, there's another very important piece of equipment too. It's the thermal plate underneath the hose. This is used for making ice in fridges. The thermal plate ensures the water inside the tub becomes very very cold. It isn't very clear in the picture but if you look closely, you should be able to see a white plate underneath the hose. 

There's a thermostat inside the bar fridge which can used to be control the temperature. James set the thermostat at a reading of about 4. The scale is such 10 is the coldest and 0 the warmest. I suppose at 10, the whole tank could possibly turn into a block of ice  :Laughing:  Here's a pic of the thermostat.



I was at James' house in the afternoon at about 4 pm. There was still some condensation on the sides of the tank. James cleaned the front piece of glass as he said he couldn't see his fish and plants with all that condensation. Here's a pic of the side of the tank.



I took a picture of the bar fridge specs. Here it is:



I'm a complete idiot as far as things like watts, volts are concerned so I don't know what the figures say. But you all should be able to figure out that a bar fridge uses much less energy than a chiller and the best thing about it, it does not give out any hot air. I know hobbyists whose tanks are cold because of the chillers that they are using but their rooms become very warm. The fish and plants enjoy but the humans suffer  :Laughing: . 

All in all, James said it costs only about Sing $200 to build the bar fridge chiller. That would be about USD $115 for American folks following this thread. Is this a great idea or what?  :Laughing: 

Unfortunately, I will be on a 4 day course tomorrow so I can't go around shopping for the parts until this Saturday. Please be patient. When I get everything, I will post the addresses where to buy them and how to rig everything up. My good friend, Melvyn Seah who also saw the chiller in James' house is going to DIY everything for me. The good thing about having friends is when you're no good with DIY, you can always get someone to DIFY (Do it for you)  :Laughing: .

James said this afternoon that anyone who wishes to participate in his next project, a chiller for large tanks, must be prepared to pay for such a chiller himself. In other words, you must be prepared to fork out something like Sing $500. There's some risk that it may not work but if everything works out nicely, you should bring home a chiller that is much more efficient than a bar fridge and takes up much less space. James needs help because he doesn't have the time to go around shopping for the parts. Cost-wise, it will also make everything much cheaper if the items were bought in bulk. James is looking for a team of about 5 persons. 

James explained the idea to me but being technically-challenged and a complete idiot, I didn't quite understand him. Briefly though, it involves using a compressor without the need for the fridge/freezer and hooking it up to something called an evaporiser and I can't remember what else. It is something that is unavailable in the market and involves some soldering work and piping. If you're game, let me know through private message and I will put you in touch with James. Please take note that neither James nor I are going to profit from the project. We'll just want something better than the chillers available in the market, that's all.

Loh K L

----------


## shortman

Wow, 70Watts for a chiller that is so far the lowest rating I could get in the market. The lowest I know for a chiller is around 110~150w.

cheers

----------


## A.Rashid

Wow, how innovative. Never knew a bar fridge can be converted or rather be use to cool down an aquarium tank. Now it really makes my hand itchy to start DIYing. heheheh fridge could also be use to store BBS eggs, bloodworm, drinks if you guys ever come down to my house for chit chat and etc.. hehehehe

----------


## shortman

Think we may have to start two different DIY a small scale one and a large scale (1000L).

Anyone know where to get cheap second bar fridge ?

Thanks

----------


## Green Baron

> James said this afternoon that anyone who wishes to participate in his next project, a chiller for large tanks, must be prepared to pay for such a chiller himself. In other words, you must be prepared to fork out something like Sing $500.


I can help with DIY the 1000 liter chiller but not ready to commit $500 to test out a chiller for such a large tank. A 1000 liter tank is beyond my league !

I am more interested in a chiller for 4ft tank. I wonder if we can use those tiny fridge that takes a 6-pack ?

----------


## timebomb

> Think we may have to start two different DIY a small scale one and a large scale (1000L).


That would be correct, Kho. If yours is a small tank (around 200 litres), use the bar fridge idea. It's cheap and running costs are very low. If your tank is large, say somewhere around 400 litres, it would be best if you wait a while and see if the next project is just as good as the first one. On paper, it sounds like a fantastic idea but like my good old teacher used to say when I was in school, "There's many a slip betwixt the cup and the lip". 

I forgot to mention in my earlier post that the room where James keeps the tank isn't air-conditioned or anything like that. The thermometer was reading 31.5 before James started the DIY bar fridge chiller working. In less than 24 hours, it pulled the temperature down to 22 degrees C. 

Loh K L

----------


## stormhawk

KL, that's a pretty efficient way of doing things but the mini-bar fridge can take up quite alot of space.

----------


## timebomb

> KL, that's a pretty efficient way of doing things but the mini-bar fridge can take up quite alot of space.


Not much more than a chiller, Jianyang. You have to think of the advantages. Besides being cheap, running costs are also much lower. Best of all, it doesn't blow any hot air. It's also silent. Compared to cooling fans, that's another big advantage. It also does not cause evaporation. 

All in all, I think it's a fantastic idea. I would have leapt into action immediately if not for the fact I will be on a 4 day course tomorrow  :Crying: 

Loh K L

----------


## stormhawk

Hmm.. something to think about. But, getting the bar fridge is no easy task, especially 2nd-hand ones.  :Confused:  

Off-Topic: There are lurkers discussing this topic elsewhere.  :Rolling Eyes:

----------


## PohSan

The bar fridge method should be able to cool down a rack of killies tanks to keep all the fishes and mosses happy. 

Regards,
Ong Poh San

----------


## timebomb

> Off-Topic: There are lurkers discussing this topic elsewhere.


Yup, I'm aware of that and there's nothing wrong with it. Just remember, you heard it first on Killies.com  :Laughing: 

Loh K L

----------


## stormhawk

Maybe we should post up a Copyright sign on the thread or just block the whole thread from being linked.  :Laughing:  That'll stop the lurkers in the tracks.

----------


## stormhawk

> The bar fridge method should be able to cool down a rack of killies tanks to keep all the fishes and mosses happy.


Well for starters, not all killies like the cool temperatures but certainly with the use of this bar-fridge chiller, we can broaden our choices of species. Maybe now we can start scheming on keeping those coolwater killies.  :Very Happy:

----------


## timebomb

The Diapterons are now within our reach  :Laughing: . There's also some discussion on Killietalk about _Austrolebias nigripinnis_ which was found to live in waters as cold as 5 degrees C.

Loh K L

----------


## ruyle

James' chiller is way cool! Hey, look, goosebumps!  :Laughing:  KL, give our thanks
to James for condescending to show us all this condensation  :Laughing:  I'd be very
interested in checking out his CO2 system, too!

Regards,

Bill

----------


## whuntley

I was going to just lurk and learn, here, but must correct something said a couple of times.

A bar refrigerator or freezer *will* warm the room, exactly like any other chiller. The amount depends on the efficiency and Wattage, but TANSTAAFL.

All refrigerators, air conditioners and chillers are heat pumps that pump heat out of one place and deposit it elsewhere. Refrigerators often just dissipate the heat with stationary coils in contact with room air. Chillers sometimes increase efficiency by blowing air past the hot coils. The process is the same. Efficiency may differ.

In Fremont, I had 150 tanks and containers going, so chilling each of those wasn't practical. I installed a small window air conditioner in one corner of my fishroom, and put _Diapterons_ and similar cool-water fish in tanks right in the outlet air blast. All the tanks were kept a couple of degrees cooler in summer, and the ones getting the direct air blast were down several degrees. What is more, the hot coils were outside, heating the back yard, and my fishroom was the most comfortable part of my house.

I also had air to all tanks. Our lower humidity made that an effective supplemental cooling effect. Probably not worth a lot in Singapore, Hawaii or Puerto Rico.  :Smile: 

The downside was my electric bills (CA had "deregulated" utilities -- HAH!) and the increased need to have a UPS to keep air going during rolling blackouts.

I see no mention here of the use of Peltier cooling. For a small isolated tank, it can be very efficient. The guts out of one of those portable 12V heater/refrigerators can pretty easily be adapted to the back of a small tank. Has anyone explored that as a cheap way to cool a killy tank?

Wright

----------


## stormhawk

Wright, you mean using those cooling coils? I've seen someone do it before but its pretty unsightly. It was on a topic I read a few months ago elsewhere. They were discussing cheaper ways of cooling a tank.

----------


## RonWill

> Using a bar fridge to cool down a tank is an idea that has been proposed and discussed many times and those who have tried it say it won't work


I believe the reason why some experiments didn't work as efficiently was the lack of conductive materials, insulation and void space.

James uncanningly got most of them right. Rubber hoses aren't the best material for conducting heat or cold, definitely less conductive than copper tubings, but by immersing a lenghty coil of hose in water, allows the passing current to cool off more rapidly (since water conducts heat better than air). Lengthy and smallish diameter of the coil is more important than a short huge-diameter hose.

Similar to concepts that apply to UV sterilization, it's the duration of exposure and flow-rate within the unit that makes it effective.

Aside from the tub containing cold water, this mass/bulk reduces the amount of void space within the bar fridge. Filling up the lower unused segment for 6-packs, white worm cultures and fish food will further reduce the empty space. IMHO, that will make the design even more efficient without having the thermostat kick in too often (not forgetting the nice cold soda or malt :wink: )

Returning water via rubber hose is not the best but it's cheaper than insulation foam over copper pipes (similar to those connected to compressors for multiple-unit air conditioners).

I suspect that the powerhead is optional since the passing water (through the coiled hose) will displace the ambient 'heat', there shouldn't be a chance for the tub to freeze. What it will do is, to provide circulation so that the thermostat gets a more accurate reading, cutting off at predetermined dial-settings (the dial isn't set for Degree Celcius reading).

My hunch tells me that if the present prototype can reduce tank's temp to 20ºC, it will work just as well for larger tank capacity if a water vessel, large enough to occupy both freezer & fridge segment, can be used together with a even longer set of hose.

To be able to achieve 22ºC in the tank is *very good* but that's excluding heat generated from more circulation powerheads, filtration pumps and metal-halide lamps.

I have no need for an aquarium chiller now but my curiousity needs to be quenched. To be able to participate in the DIY, even if it's to rig these up for others, will be a fun experience.

Let me know if James need an extra pair of hands.

----------


## stormhawk

Ron, I think a bar fridge would look neat at your rack. Mini beer refrigerator perhaps? Dual purpose, apart from super-cooling your main system.  :Laughing:

----------


## RonWill

> Ron, I think a bar fridge would look neat at your rack. Mini beer refrigerator perhaps? Dual purpose, apart from super-cooling your main system.


Jian Yang, I was actually thinking along the line of combined chiller for tank and *beer fermenting* but any blind man can see I'm quickly running out of 'free' space :wink:

----------


## PohSan

> Ron, I think a bar fridge would look neat at your rack. Mini beer refrigerator perhaps?


Think that is no more space after filling up with all his cultures.

PS: Now I remembered that I missed the beer yesterday night.  :Confused:  

Regards,
Ong Poh San

----------


## stormhawk

Poh San, its not just the culture. His new 2ft sump already took up HALF the bottom area so a bar-fridge would be pretty squeezy. Shucks, if it was up and running we'd be having a mini pub at Ron's Corner.  :Laughing:

----------


## timebomb

> A bar refrigerator or freezer *will* warm the room, exactly like any other chiller. The amount depends on the efficiency and Wattage, but TANSTAAFL.


For those who may be wondering what TANSTAAFL stands for, it means "There Ain't No Such Thing As A Free Lunch". 

Hey, Wright, can't you be wrong for once  :Laughing: . 

You're right as usual. I didn't mention that there's a heat transfer because it wasn't a big deal to me. But if the folks like to know, the sides of the bar fridge feels hot to the touch. It's so hot, in fact, you can't touch it for too long or your fingers will get cooked  :Laughing: . But it's not anything to worry about. It's hot, not because of the modifications, but that's how the fridge works.

Loh K L

----------


## whuntley

> Wright, you mean using those cooling coils? I've seen someone do it before but its pretty unsightly. It was on a topic I read a few months ago elsewhere. They were discussing cheaper ways of cooling a tank.


No, I was referring to the little flat thermo-electric plates that use the thermocouple effect backwards to move heat from one surface to the other. They have become quite cheap and efficient in recent years. There are even some made to chill the CPU for home computers.

You need a finned aluminum heat sink on the air side, and thin glass to keep from insulating too much from the water side. I doubt if the cooling would stress glass enough to break it if you use good heat-sink compound to assure uniform contact.

Basically, you apply up to 12V across the thin plate, and one side gets cold while the other gets hot. Reverse the voltage to switch from heating to cooling. The entire thing, built into a portable picnic cooler, costs US$40-60 here, including a fan and heat sink! I think the CPU coolers are even cheaper, but haven't priced any lately.

Wright

----------


## PohSan

Talking about CPU cooling, I ever came across an article from a PC magazine that discussed on CPU cooling with water and coolant with compressor. Seem like today's CPU is getting hotter and maybe in near future, all PC come with standard coffee maker and warmer.

Regards,
Ong Poh San

----------


## RonWill

Wright, the cooling coils that Jian Yang mentioned are similar in design to the heating element found in kettles. I've seen those cooling coils in seafood restaurant's tanks, where there're lobsters and other delicacies waiting to land in the wok.

I first heard of Peltier cooling whilst learning to stretch my dollar (or CPU's limits ie. overclocking) but didn't follow the application for tank cooling. I think the limitation to that was controlling the desired temperature.




> Seem like today's CPU is getting hotter and maybe in near future, all PC come with standard coffee maker and warmer.


 Poh San, your PC already comes with a ejectable cup holder (cdrom tray  :Laughing:  ) If you miss the beer, swing by the week after the meeting at Eco's. It should be well chilled by then.

----------


## A.Rashid

> any blind man can see I'm quickly running out of 'free' space :wink:


Ronnie, perhaps since he's(Jiangyang) alway there at your house why not make him to some spring cleaning and get things reorganised. And perhaps the laundry poles can use a retractable thingie mounted to the ceiling. :wink:

----------


## whuntley

> I first heard of Peltier cooling whilst learning to stretch my dollar (or CPU's limits ie. overclocking) but didn't follow the application for tank cooling. I think the limitation to that was controlling the desired temperature.


That's the easiest part. I always wanted to do a design that heated *and* cooled. For simple cooling control, you can use a modified aquarium thermostat and a NC relay to just turn the unit on when the system calls for cooling (the thermostat switch opens).

A controller that reverses voltage to do both is a slightly trickier problem, I think. (2-pole, double-throw relay? SCRs?).


Wright

PS. Burned out heaters can make excellent thermostatic controls. Short-circuit the heater connection and find the side of the line cord that was attached to the heater and not the switch. Cut that wire at a convenient spot, and install a simple 2-prong socket to the two ends that you can plug any simple (non-thermostat) heater into. Great for an under-tank reptile heater.

----------


## CM Media

Wow!  :Surprised:  

This project comes just in time! I was searching for a chiller for the past few months and was sort of put off by the high output of heat generated by the chiller.

I'll like to take part in the project and build one for those demanding killies! If possible count me in.

I'm checking with a supplier for secondhand mini fridge. Those who are interested, please write down your name. I'll then talk to the supplier but no promise. :wink: I presume the cost should be around 50% less as compare to a new mini fridge.

----------


## PohSan

Let me starts the list:

Mini Fridge
-------------------
1) Ong Poh San (budget:S$100)

Regards,
Ong Poh San

----------


## bad_boyz

Hi Loh K L I already have a mini bar. Can u find out from James what els i would need and how much would it cost? Thanx

----------


## shortman

Guys,

I was thinking of using copper pipe in the fridge but not sure it is aquarium safe.

I have the necessary power drill and hole cutter and can pass among all of us, and one tube of sealer should be enough I think.

What is the size of the bar fridge should we be getting?

Here is the last count list for the small scale chiller. Pls add yourself in with the next post. :-)

1. Gan C W
2. PohSan (budget $100)
3. A.Rashid
4. Au S L
5. Shortman

Any more people ? :wink: 

Cheers

----------


## timebomb

Folks,

I can understand your eagerness to DIY your own chiller too but I would suggest you don't jump into the project yet. A freezer should work better than a mini bar fridge. If you start buying now, you may regret it later.

Let's discuss it a little more before deciding what we should do. Ronnie made a good observation when he said the longer the hose, the more effective the chiller will be. A freezer should be able to take a much longer hose than a bar fridge and it wouldn't cost much more, I suspect. I think Ronnie's right too when he said the pump in the tub could be an optional item. I think it actually generates more heat. It is there probably to keep the water in the tub from freezing but I wonder if a block of ice surrounding the hose is more effective than just cold water. 

Kho suggested using copper but I think it will be much more expensive than using PVC. There could be some material that's more conductive than PVC but just as cheap. 

I received a call today from a friend who said he found a shop that sells mini bar fridges for a very competitive price and they are brand new. They come with one year warranty but I doubt the manufacturer will honour it if we drill holes in the fridge. In any case, I prefer a freezer to a fridge so I'm keeping my options open. 

Anyway, if any of you are impatient and want to embark on the project right now, I hope you will share your experiences with us. I offered to be the guinea pig but if you want to volunteer, please be my guest  :Laughing: 

Loh K L

----------


## cheeboonyong

> Maybe we should post up a Copyright sign on the thread or just block the whole thread from being linked.  That'll stop the lurkers in the tracks.





> Chk this out on DIY Chiller 
> 
> 
> http://www.aloha.net/~hqf/indexdonschiller.htm 1999 design 
> 
> http://www.aloha.net/~hqf/indexjrosechiller.htm 2000 design


I'm not sure if anyone has followed up on the links. The 2000 design actually is very similar to what James is doing. I'm not an expert on cooling, so it would be great if anyone can point out what is radically different between the 2 designs. Looks similar to me...

It's just incredible the amount of interest that a good picture can generate. Schematic drawings always work in theory but don't always have the persuasive power of a "live" demo. Considering the design existed since 2000 (maybe even earlier by somebody else, who knows!?!) but nobody here seems to know about it, yet when a working model is presented, everyone is all excited about it. The power of advertising...

Sorry for digressing...

----------


## shortman

Kwek Leong,

Yet jump into the DIY yet as I couldn't get the length of the hose/pipe right. What is the length such that it will be more efficient to transport the heat away in the water within the fridge?

I am thinking of using the filter pump to pump the water into the fridge.
The size and the temperature control in fridge is a important factor if not we have to find a way to preset the temperature in the aqurium.

It is not cost effective to auto on/off the fridge and will it shorten the lifespan of the fridge.

Thanks

----------


## timebomb

> Sorry for digressing...


Nothing to be sorry about, Boon Yong. Actual pictures definitely will generate a lot more interest than diagrams. I'm not sure where James got his idea but it wouldn't surprise me if he found his inspiration on the world wide web. The web is such it's a wealth of information if one bothers to look. In any case, James deserves a lot of credit for putting an idea into action even if he wasn't the guy who came up with the idea in the first place.

I took a look at the 2 urls you posted and other than for some modifications, the diagrams look similar to James' setup. The diagrams don't tell what material the hose is made of though. If I saw correctly, I think they are normal rubber hoses which we know, are not very effective. There's also no mention of a thermal plate which I think is a quite important item for the chiller to work effectively. 

The second diagram seems to show a picture of a freezer which as I've said before, is probably more space efficient than a bar fridge. Frankly, it's hard to get excited over a diagram as it does not convey the idea as well as a picture. 

It makes me wonder sometimes why there are not more pictures on some web sites that have very good ideas. Are digital cameras in other countries less common than in Singapore? 

Loh K L

----------


## cheeboonyong

> Are digital cameras in other countries less common than in Singapore?


Guess they weren't so common back in 2000.  :Laughing:  

But you're right, a picture does indeed say a thousand words. I very much enjoyed reading your moss wall article with all the nice pictures. Show exactly step by step. Maybe video over net would be the next big thing??? But please don't film the moss growing in real time :wink:

It would be great if you guys could put a pictorial guide during your DIY setup. Those lazy people like me who wants to know better but don't want to get their hands dirty would greatly benefit from it!  :Very Happy:

----------


## timebomb

> What is the length such that it will be more efficient to transport the heat away in the water within the fridge?


Obviously, the longer the better, Kho. The diameter of the hose is important too. Ronnie who's pretty sharp knew right away that it has to be small or else the flow will be so slow the water may freeze. We don't know which is the best length as we have to see how big is a freezer compartment before we can decide. Get the right freezer. It has to be small enough to fit into my fish cabinet or else it will stick out like a sore thumb in my living room. After we buy the freezer, we can work out how long the hose should be. Freezers are not usually used in households so they are not sold as commonly as bar fridges. But if we look hard enough, I'm sure someone will find a shop that sells a freezer of the right size. 




> I am thinking of using the filter pump to pump the water into the fridge. The size and the temperature control in fridge is a important factor if not we have to find a way to preset the temperature in the aqurium.


How the temperature is preset will depend on how cool you want your tank to be, I think. We all would love to see condensation but it can be quite a chore if we have to clean the glass every day. As for pumping the water into the fridge, I think it's the other way round. Water will flow into the fridge through gravity and the filter will pump it up back into the tank.




> It is not cost effective to auto on/off the fridge and will it shorten the lifespan of the fridge.


Definitely. But I don't think we will have to on off the fridge all the time once we know what's the best reading on the thermostat to set it on. We probably have to monitor it closely at first and find out for ourselves what's the best reading. Everyone's tank is different. Size, water circulation, room ambient temperature - these factors will affect the effectiveness of the chiller.

Loh K L

----------


## timebomb

> Those lazy people like me who wants to know better but don't want to get their hands dirty would greatly benefit from it!


I'm glad you like my moss wall article, Boon Yong. It was my very first article and I was quite surprised to find out recently that it has been translated into Hungarian on some other web site. Whaddaya know?  :Laughing: 

I'm all tied up with a course this week so I can't spring into action until this Saturday. Melvyn, my good friend called just now and he's keen to work on the project too. We will probably go shopping for a freezer this weekend. When I get all the parts, I will post the addresses where you can find them. I will also take step by step pictures when Melvyn rigs up the whole thing. 

It's for lazy bums like you that people like me exist, Boon Yong  :Laughing: . 

Loh K L

----------


## Green Baron

> Folks,
> I can understand your eagerness to DIY your own chiller too but I would suggest you don't jump into the project yet. A freezer should work better than a mini bar fridge. If you start buying now, you may regret it later
> ....
> 
> Anyway, if any of you are impatient and want to embark on the project right now, I hope you will share your experiences with us. I offered to be the guinea pig but if you want to volunteer, please be my guest 
> 
> Loh K L


Kwek Leong,
Agree with you that we should not jump the gun. As pointed by Kho and Ronnie, there are still rooms for improvement and since you have very kindly volunteered to be the guinea pig, we should wait and learn from your experience. In fact we could all share the cost of this 2nd prototype so that you don't have to bear it all for our benefit !

If I am in in town this weekend, I will drop by your place to see how the thing is setup. I think we can wait another week or two ;-)

What are important to me are size and aesthetics as the chiller will be sitting in my living room. Do you think the chiller can be placed inside the cabinet under the tank ?

----------


## timebomb

> Do you think the chiller can be placed inside the cabinet under the tank ?


I'm not sure about that, Gan. There are some chillers that are pretty small but almost all open at the top. The freezer may fit into the cabinet but there may not be enough space to open it. 

Besides putting it inside the cabinet, I have another option, which is to position it in my balcony which is just behind my main tank. I'm reluctant to do that though because the balcony is exposed to weather conditions. If it rains heavily, my balcony gets all wet. On normal days, it gets very hot. 

Loh K L

----------


## timebomb

> In fact we could all share the cost of this 2nd prototype so that you don't have to bear it all for our benefit !


Thanks for the offer, Gan but there's no need to do that. I don't mind being the guinea pig as the cost isn't very high. I was told this evening that there's a shop that sells mini-bar fridges for less than a hundred dollars each. And they are not second-hand. Can't confirm it though as I've yet to visit the shop myself.




> If I am in in town this weekend, I will drop by your place to see how the thing is setup. I think we can wait another week or two ;-)


You're always welcomed to visit me but I don't know if there's enough time to rig the whole thing up. I forgot I have to be at Eco-Culture this Saturday evening. 

Loh K L

----------


## turaco

Just my observation, wonder how long can the bar fridge last(life span) :Rolling Eyes:  ? It's like running a fridge with it's door open, the fridge will work very hard in order to reach its desire temperature. In normal closed door fridge, the thermostat will cut off once it reaches the coldness, thus the fridge get to 'rest'. But in the case of this experiment, it seems like it's going to run non stop till it get burnt out? Maybe a higher power fridge will solve the problem?

----------


## timebomb

> JBut in the case of this experiment, it seems like it's going to run non stop till it get burnt out?


I'm not sure, Gan but I think it won't work the way you described. It will probably use up a lot of energy in the beginning but once the tank is cooled, only a litle energy is needed to keep it at that temperature. The door's always closed and there's no reason to open it unless to check the equipment. Opening and closing the door will cause the fridge to use more energy, of course.

Loh K L

----------


## turaco

> The door's always closed and there's no reason to open it unless to check the equipment.


What I mean is, there's an external source of heat(tank's water) that is constantly entering the fridge, stressing the mini fridge, which is what it is not designed for. While the tank may be cooled eventually, the low-powered bar fridge had already worked double hard. That is why I'm asking about it's durabilty.

----------


## whuntley

Placing the chiller under the cabinet will defeat the purpose unless the cabinet is very well ventilated to the room. The hot case will add as much heat back as is being extracted or even more. The objective is to pump heat *out* of the tank and put it *elsewhere*.

Copper tubing has high conductivity but could be dangerous to the inhabitants of the tank. If a pH "crash" happens, the copper can be dissolved (ionized) and enter the water. Bye-bye inverts, and maybe fish, to heavy metal poisoning. Even worse if solder filtting are used instead of compression fittings. [I once killed a tank of FIL because I left the lead anchors on some plants from the store and the pH was quite low. Ugly scene!  :Crying:  ]

Aluminum tubing is probably safer, as the inside surface forms a solid layer of aluminum oxide (sapphire) that sort of keeps it inert. I have never heard of a (convincing) toxic problem with aluminum in aquaria. Never used this much in water contact, though.

As far as patents go, reef folks and stores have used refrigerators in place of chillers for over 50 years, so any patent on that idea is long expired or invalidated by "prior art."

From a cost standpoint, polyethylene tubing, like that white frosty stuff used for refrigerator ice-makers, is the most practical, but it doesn't have the conductivity of metal. Use as large a diameter and thin wall as can be coiled in your bucket or tub to essentially fill it. Fill with salt (or sand) and wrap around a dowel or pipe before dunking in boiling water if you want tighter coils. [Salt is more expensive but easier to remove. It washes out.]

Use an aluminum pot to hold the coil. The heat transfer from air to water will be greatly improved over any plastic tub or bucket. Even a galvanized bucket or wash-tub would be OK, as the zinc doesn't contact tank water at any point. Stainless steel has lower conductivity, so think twice about using it, even if it will last longer. The metal container will increase temp. gradients and stop the need for an inside pump, probably, by convection stirring. Even an old glass aquarium with thin walls might be a little better than the poly pan shown in one photo (not sure about that, though).

Ice is a fairly good heat-transfer insulator, so I don't think you want any in the tub at any time. It also will block convection currents.

Wright

----------


## timebomb

> While the tank may be cooled eventually, the low-powered bar fridge had already worked double hard. That is why I'm asking about it's durabilty.


We won't know the answer to that question until we have used it for a while, Gan. The fridge may go kaput after a while but that's a risk we have to live with if we go DIY. You can be patient and wait several months or a year or 2 to see how things work out but I doubt anyone's that patient  :Laughing: . As it is, I'm having a hard time asking everyone to rein in their horses  :Laughing: . 

Loh K L

----------


## RonWill

> ...who's pretty sharp knew right away that it has to be small or else the flow will be so slow the water may freeze. We don't know which is the best length...


 One small correction. Kwek Leong, he purpose of a smaller diameter hose is for it's flexibility and also the fact that you can pack a longer length of hose within a limited space. The longer the path taken, the better the freezer/fridge is able to cool the travelling water till it leaves the 'chiller'. I would hazard a guess that there'll be no chance for the tub of water to freeze over as the incoming water will be constantly 'defrosting' it with a constant flow rate.

The best length is, of course, the longer the better.




> Just my observation, wonder how long can the bar fridge last(life span) ? It's like running a fridge with it's door open, the fridge will work very hard in order to reach its desire temperature. In normal closed door fridge, the thermostat will cut off once it reaches the coldness, thus the fridge get to 'rest'. But in the case of this experiment, it seems like it's going to run non stop till it get burnt out? Maybe a higher power fridge will solve the problem?


 Gan, if you can see the thermostat plate under the coil of hose, the water in the container is set by the dial. Once the preset is reached, the compressor doesn't kick in until it's needed.

The fact that the water-filled container has considerably reduced the internal space, the freezer actually don't have to work very hard. Much lesser than the home fridge where the kids keeps opening it for snacks! In that regards, an half-filled fridge will take longer to cool down again when compared with a stuffed-up fridge. A distant analogy might be using a high BTU air-conditioner to cool a small room against a lower rated unit to cool a large room.

If you look at better designed whiteware (another nice words for kitchen appliance like washers, dryers, fridge, etc), there are vertical standup front-access freezer (yes, only freezer) that has drawers. The drawer retains as much of the cold air while the door is opened. Think back to the chiller design. The main bulk of the available space is already taken up and since the water (in the container) is already quite cold, plus the fact that it's rarely opened, the 'cold-loss' is quite negligible.

Anyone doubting that this will work can try something I've tried, albeit some years ago.
Get the largest polyfoam box you can find (either from fishing supply stores or your wet market).
Cut out 2 access holes for the water inlet & outlet from the canister filter.
Coil up some smaller diameter rubber hose to fill up the bottom half of the box.
Cover the hose with crushed ice and fit 2~3 solid blocks of ice over it.
Run your filter as per normal.

... then get back to me with the details (how long the ice last and how low a tank temp you're able to achieve). Upfront, I'll tell you that if the temperature doesn't drop to 22ºC, you're doing it wrong :wink:

BTW, did I tell you that I'm a very curious animal?

----------


## timebomb

> Placing the chiller under the cabinet will defeat the purpose unless the cabinet is very well ventilated to the room.


Wright, wouldn't it be great if the cabinet below the tank heats up? Wouldn't it be something like undergravel heating cables? Very few hobbyists here use heating cables as our tanks are never cold enough to make a difference. But I wonder now whether it's worth doing it.




> Aluminum tubing is probably safer, as the inside surface forms a solid layer of aluminum oxide (sapphire) that sort of keeps it inert.


Aluminium tubing? Hmm, that's a new one for me. I don't know where we can get such tubings in Singapore. It could possibly raise the price of the chiller by quite a fair bit. The PVC hose James is using now costs only Sing $1 for a feet. 




> As far as patents go, reef folks and stores have used refrigerators in place of chillers for over 50 years, so any patent on that idea is long expired or invalidated by "prior art."


Patenting the idea was never a consideration, Wright. Nothing new was invented anyway. It's just assembling equipment used for other purposes.




> From a cost standpoint, polyethylene tubing, like that white frosty stuff used for refrigerator ice-makers, is the most practical, but it doesn't have the conductivity of metal. Use as large a diameter and thin wall as can be coiled in your bucket or tub to essentially fill it. Fill with salt (or sand) and wrap around a dowel or pipe before dunking in boiling water if you want tighter coils. [Salt is more expensive but easier to remove. It washes out.]


That's a great tip, Wright. I will surely try using salt to coil it when I get my hands on the PVC tubing. But I don't understand what you meant by large diameter? Wouldn't that slow the flow of water? Hmm, I think I got you now. Slowing the flow will keep the water in contact with the cold water in the tub longer, thereby lowering the temperature further. Is that right?




> Use an aluminum pot to hold the coil.


That's a great idea. Metal conducts heat much better than plastic. Getting a aluminum pot should be much easier than the tubings. 




> Ice is a fairly good heat-transfer insulator, so I don't think you want any in the tub at any time. It also will block convection currents.


Got that, Wright. But wouldn't the water freeze if there's no powerhead to keep the water moving?

Loh K L

----------


## timebomb

> ... then get back to me with the details (how long the ice last and how low a tank temp you're able to achieve). Upfront, I'll tell you that if the temperature doesn't drop to 22ºC, you're doing it wrong :wink:


I tried what you suggested years ago, Ronnie and it didn't work. I didn't immersed the hoses into iced water though. I had my 2 external cannister filters buried up to their necks in ice in a styrofoam box and after all the ice had melted, the temperature in my 4 feet tank didn't even drop by half a degree. Plastic cannister filters are not great conductors of heat, that's what I gathered.

Loh K L

----------


## RonWill

> Plastic cannister filters are not great conductors of heat, that's what I gathered


I recently replaced an impeller rod (satay stick) for the real ceramic rod and the accompanying rubber bushings. Tested the Eheim 1060 in a small blue pail and let it running, water being re-circulated at a fast rate.

About half an hour later, the water was warm to the touch and the thermometer read 41ºC  :Exclamation:  

By having the 2 pump motors within the same confine simply means that what cooling the ice achieved is negated by the heat displaced... kinda like running a heater and air conditioner on at the same time in the same room. That's why you don't see the main pump in the fridge. Makes sense? (alternatively, it's like having the AC compressor inside the room you're trying to cool)

Further more, the path of water within the canister is nothing compared to coiled tubings. It is the prolonged intimate exposure to the cold that we want to achieve. I should have mentioned that smaller diameter rubber hoses _usually_ have thinner walls and easier to to coil up instead of larger thicker ones.

The earlier mentioned 22ºC was observed in my 4footer as well, considering I had 2 x 150w MH lights going. I gave up only because I've gotten tired of refilling the ice.

----------


## whuntley

> Placing the chiller under the cabinet will defeat the purpose unless the cabinet is very well ventilated to the room.





> Wright, wouldn't it be great if the cabinet below the tank heats up? Wouldn't it be something like undergravel heating cables? Very few hobbyists here use heating cables as our tanks are never cold enough to make a difference. But I wonder now whether it's worth doing it.


No it isn't the slightest like cables. They cause little convection currents because they are local hot spots with nearby adjacent cool areas. Uniforn under-tank heating does nothing to cause that intra-substrate circulation.

What is more, no one uses cables any more after Tom Barr showed how useless they really are. A few die-hards like Geo. Booth, maybe, but mostly they are in tanks much too hard to tear down and fix.




> Aluminum tubing is probably safer, as the inside surface forms a solid layer of aluminum oxide (sapphire) that sort of keeps it inert.





> Aluminium tubing? Hmm, that's a new one for me. I don't know where we can get such tubings in Singapore. It could possibly raise the price of the chiller by quite a fair bit. The PVC hose James is using now costs only Sing $1 for a feet.


I don't think aluminum tubing is much more expensive than that. It has nearly replaced copper in many dehumidifiers and AC units. I would not be inclined to use any vinyl hose because the plasticizers in it are harmful over the long haul. Note that hospitals have banned "Tygon" and similar tubing for any patient contact stuff. Stick with polyethylene without any plasticizers. 





> From a cost standpoint, polyethylene tubing, like that white frosty stuff used for refrigerator ice-makers, is the most practical, but it doesn't have the conductivity of metal. Use as large a diameter and thin wall as can be coiled in your bucket or tub to essentially fill it. Fill with salt (or sand) and wrap around a dowel or pipe before dunking in boiling water if you want tighter coils. [Salt is more expensive but easier to remove. It washes out.]





> That's a great tip, Wright. I will surely try using salt to coil it when I get my hands on the PVC tubing. But I don't understand what you meant by large diameter? Wouldn't that slow the flow of water? Hmm, I think I got you now. Slowing the flow will keep the water in contact with the cold water in the tub longer, thereby lowering the temperature further. Is that right?


You don't need anything for clear polyvinylchloride tubing as the plasticizers make it pretty limp. The frosty polyethylene is fairly stiff and resists really tight bends without a bit of heat inducement.

Larger diameter means more total water flow (GPH) and less back pressure on the pump. If you use the 1/4" refrigerator ice-maker tubing, there will be too little volume and danger of freezing, IMHO.




> Use an aluminum pot to hold the coil.





> That's a great idea. Metal conducts heat much better than plastic. Getting a aluminum pot should be much easier than the tubings.





> Ice is a fairly good heat-transfer insulator, so I don't think you want any in the tub at any time. It also will block convection currents.





> Got that, Wright. But wouldn't the water freeze if there's no powerhead to keep the water moving?


Not if you have enough tank water flowing through to keep it from happening. Setting flow volume and the refrigerator's thermostat will be a part of the initial fine tuning. Increase flow or reduce thermostat to avoid any icing up.

Wright

----------


## victri

To avoid freezing of water in the tub, maybe can consider automotive antifreeze coolent. They have very low freezing points, and I've used them in my car in temps of -40deg C (when I lived in Canada). There'll be a danger of poisoning if any of that leaks into the tank though. You'll need to totally seal off the hose and tub to be safe.

I'm curious as to how the overall flowrate might be affected, and how that in turn might affect the CO2 dissolve rate for those running in-line CO2 reactors.

----------


## FC

KL and Gan,
As Wright explained, fridge (or air-con) provides cooling by extracting heat from the target zone (a compartment or room). As such, the efficiency of the fridge depends very much on how this heat (you felt when you touch the back of the fridge) is facilitated to be put away.
Therefore, an enclosed cabinet would not be a feasible location for the fridge where air circulation is bad. Unless, of course, you place a matching sized exhaust fan on the cabinet.

Wright, Ronnie and experts,
I have an idea which I need your comments. In place of the piping, the tub, etc, can I use a small radiator with fan like those used by small motorcycle? It is fully made with aluminium.
I will then place a thermostat that measures the tanks water temperature. This thermostat will in turn control the radiators fan (on/off), the fans suction side facing the evaporator. With these, I hope to achieve:
1) high efficiency of heat transfer
2) simple and accurate tanks water temperature control scheme
3) more space for other usage
Kindly advise if this would work.

----------


## whuntley

Yes, it should work, but you are adding the fan's heat to the water. I think the liquid bath is better. Can you submerge the radiator?

I'd probably use a separate water pump and have it turned on and off by the thermostat, too.

Wright

----------


## stormhawk

> JianYang, Ronnie and Freddy should I count you in?


Kho, I'd be glad to land a helping hand. Didn't notice this post of yours till tonight. Pardon the blurness  :Opps:  Anyways, tell me when you need some help, with hands that is, and I'll drop by. Money-wise, I don't think I have enough to invest in a small bar-fridge, besides, my dad will kill me if I add another bulky item to the already messy tank area.  :Laughing:

----------


## shortman

Once we have pick the right fridge, next was to strip the fridge to see if it is possible to add an additional temperature controller into the fridge.

The ideal is to control the tank water temperature and reduce the running cost. Parts can be easily get from the electronic/electrical store in town. 

But we will wait for what Kwek Leong has come up with the DIY prototype.  :Smile:  

Use of aluminum pipe in the fridge is a good ideal in this case we may not need the water tub and aviod the it being ice'ed. Running water in the pipe will not cause the water in the pipe to freeze.

Cheers

----------


## shortman

Since we are on this topics and for the interest of the community here,
check this url DIY: Ultimate Ghetto Chiller 
http://www.saltwaterfish.com/vb/show...ht=%2Afridg%2A

Best Regards

----------


## Green Baron

> Since we are on this topics and for the interest of the community here,
> check this url DIY: Ultimate Ghetto Chiller 
> http://www.saltwaterfish.com/vb/show...ht=%2Afridg%2A
> 
> Best Regards


A picture from the above mentioned post  ::smt023:   ::smt026:   ::smt026:   ::smt026:

----------


## shortman

Gan,

Did see beer ?  :Beer Time:  

Cheers

----------


## timebomb

Hi, fellas,

I went looking around for a freezer yesterday and the best one I found was at Carrefour's. They have a freezer that is 106 litres going for $269. The freezer is a bit too large for my liking so I'm going to shop around some more tomorrow. I have the contact for a shop that specialises in freezers but they aren't open today. 

Anyway, here's the plan:



With 106 litres, I think I can coil maybe 30 feet of PVC hose  :Laughing: . It's a bit overkill, I know but I don't do things in small measure  :Laughing: . The freezer will be behind my tank in my balcony where it's hidden from view. 

I don't intend to put in a plastic tub or an aluminium container to hold the hose as the compartment of the freezer is one big opening. I will just fill it up with water and submerge the hose inside. As for using a powerhead to prevent the water from freezing, someone said if I'm concerned with that, I can simply use an airline connected to an air pump to aerate the water. It should work just as well as a powerhead, he said. I wonder if that's correct? 

I wonder too where I should drill the 2 holes. Would it make any difference if they are on the same level or would it be better if the inlet is higher than the outlet? Or vice versa? I don't want the holes to be on top as the freezer's cover is there. The diagram shows the 2 holes near the top of the freezer. Would it be better if they are lower?

Wright, I checked out the polyethylene tubing you recommended and I find them to be too stiff. They are also thicker in diameter and more expensive. So I think I will use PVC. 

The wattage for the freezer is 118 watts. According to Freddy, multipying the wattage by 0.12 would give the electric costs a month. So that would be something like $14.16 per month. That would be if the freezer runs non-stop 24 hours a day but I expect the bill to be lower as there's a thermostat to control the temperature. Anyway, $14.16 is just slightly more than what I spend on cigarettes everyday so it isn't a big deal to me. If I want to save, I should give up the damn weed instead. 

Comments, anyone? Do you think my 380 litre tank will turn into a block of ice if I set the thermostat at it's coldest reading?  :Laughing: 

By the way, guys, I looked at many mini bar fridges yesterday but didn't see a single one I liked. Unlike the one in the picture Gan posted, the compartments inside bar fridges I saw are always divided into 2. Most times, the lower one is smaller as the compressor located at the back of the fridge takes up some space. It would be difficult to coil a long length of hose inside a bar fridge but if your's is a small tank, then maybe it wouldn't make any difference. But I still think it's a waste of space even if you use the lower compartment to store beer. 

Loh K L

----------


## shortman

> Comments, anyone? Do you think my 380 litre tank will turn into a block of ice if I set the thermostat at it's coldest reading?


Kwek Leong,

Yes, given the right condition and time it will turn into block of ice as I saw it in the wet market.  :Sad:  

The closer I can find is this one in ebay.com.sg LG make.


Best Regards

----------


## timebomb

Hi, fellas,

I went to 2 different places to look at freezers today but didn't see any that was smaller than the one in Carrefour's. Melvyn was with me today and in our discussions, we came to the conclusion that a bar fridge won't work well for a big tank. Chances are, in the case of a bar fridge which has much smaller space to hold the coiled hose, the compressor will have to run non-stop and therefore, willl burnt itself out very fast. As I've said, the side of the bar fridge James is using was hot to the touch. So hot, it will roast your fingers if you leave them there.

My wife runs a provision store so I'm asking her for help. There's a brand of ice-cream in Singapore called Potong and they are sold in freezers that are of the right size. The problem with getting this freezer is that it isn't for sale. The company that markets Potong imports this freezer for their own use only. I'm keeping my fingers crossed that my wife can persuade them to sell one to me.

Loh K L

----------


## ReDDeviLs

Hi guys, happen to saw this thread here.. 
i have a 600L tank and i'm very interested in this cooling system idea.
infact im running a marine tank and i need to cool the tank else my corals will die from the heat.
I have been searching for a chiller that can support my tank but the price are way too expensive ranging from $800-$2000
wonder if this DIY project can work.
If this project can work i would be very very interested  :Smile:

----------


## FC

> As I've said, the side of the bar fridge James is using was hot to the touch


Fridge, like most cooling equipment, removes heat away from the target zone. The heat you expereinced showed that the fridge is pumping the heat out and deposit it on the casing. It is normal and should be hot at the pressurised part of the system.
For your information, anything that is too hot to touch is above 50~60 degree celius.

----------


## Kenji80

Yesterday I saw 1 freezer at Suntec Courts and the cost is around $250. 

Brand is Akira and Dimesion is 60 depth * 37 width * 84 Height cm.

----------


## timebomb

Okay, fellas,

I'm in touch with the guys from Potong ice-cream. We spoke on the phone and he said their freezers are of size about 1 ft X 2 ft X 3 ft. That would be 30 cm X 61 cm X 91 cm. A new one, he said, costs in the region of Sing $500 but a second-hand one can be had for $100 over dollars. He couldn't be specific on the phone so I can't confirm the details. 

I'll be visiting their factory tomorrow to take a look. I wonder if any of you are interested. The Potong ice-cream freezers, as far as I know, are not for sale anywhere. All I've seen so far are too big for my liking. With a freezer, there's efficient use of space as it has only one compartment when compared to a bar fridge which comes with 2 compartments.

Freddy, I know there's heat transfer but if the compressor is shut off by the thermostat now and then, I believe the side won't be that hot. Am I right? An overworked fridge will burnt itself out very fast. Would that be correct?

Loh K L

----------


## FC

> An overworked fridge will burnt itself out very fast. Would that be correct?


Most probably.
One way to go around it is the use of timer. Setting example: round the 24 hr timer, turn off the fridge for 15 minutes (=the single click) every hour.
With some trial and error, we can even control the water temperature by timer. Very much like the way we control the CO2. Example:
During the day: turn off for 15 minutes every hour
During the night: turn off 15 minutes every 45 minutes

----------


## timebomb

Thanks for the tip, Freddy.

I have another question. The side of the bar fridge James is using is where the coils are located. He drilled the 2 holes on the cover but I don't intend to do that when I get my freezer. My 2 holes will be on one side of the freezer. I asked several times but the people who sells freezers don't know where the coils are located. I'm kind of worried that when I drill, I will hit and puncture the coils which could be on one side or possibly, both sides of the freezer.

What do you think?

Loh K L

----------


## stormhawk

KL, if the Potong freezer is the one made with sliding plastic/glass covers then you can just drill through the cover instead of drilling somewhere where you may puncture the coil. The Potong freezer however has one drawback. Its quite thin in width but the height of the freezer may play a major role if one wants to incorporate this into his tank stand/cabinet. I did see a very small mini-bar fridge for sale recently and it was highly suitable for this purpose since it was small enough to squeeze into a cabinet/stand.

Found another purpose for the fridge apart from the chilling factor and ideas like a beer fridge. It seems that since some of us do utilise frozen foods for our fishes and almost everyone has a can or a canister of BBS eggs lying around, the fridge can become a place to consolidate all these items. Saves up valuable fridge space in the home fridge and certainly prevents our resident MHA (in my case my Mom for now) from complaining about frozen worms and cans of eggs in the fridge. :wink:

----------


## FC

KL,

You can trace/find out the coil location by first running the fridge for about 5 minutes (not too long). Touch the whole body (ahm, I mean the fridge  :Laughing:  ) with 2 fingers. Of course, you knew where it is warm, there is coil.

----------


## Green Baron

I went to Best Denki today to checkout the fridges. The smallest is from LG, similar to the one posted by shortman :


It is call LG Bar Fridge, 46L, 433mm(W)x450mm(D)x501mm(H) selling at S$169. The other brands are slightly bigger (~51L) and going for around S$190.

For the DIY chiller, I only need it to bring the water temperature to 25C~26C and if possible, chill a 2ft and a 3ft tanks which are beside each other. And preferably be able to fit in the cabinet with the door removed or modified ;-)

At Takashimaya, I saw a few very compact (17L) Japanese brand drink chillers/warmers. The brand is Stylus. They are probably underpowered for big tank but maybe good enough for 2ft tank ?

----------


## timebomb

Hey, guys,

I got my freezer!!  ::smt026:  

I'm exhausted from bringing it home and running around to buy the other items necessary to rig up the chiller. I'm going to bed now and will post the pictures tonight.

Loh K L

----------


## timebomb

Okay, fellas,

Here's a picture of the freezer I bought today.



The external dimensions are 66.5 cm (Length) X 35 cm (Width) X 84 cm (Height). It's the smallest freezer I've seen so far. I bought it second-hand from the boss of Potong ice-cream who said a new one costs more than $500. He sold this one to me for $150 but don't quote me as he said he wouldn't sell the freezer to me at that price if not for the fact my wife is going to retail his brand of ice-cream  :Laughing: .

As you can see, it has only one compartment which is about 65 litres in volume. I checked around and they say it's not wise to fill up this compartment with water as it may leak. So I'm going to make a tank which is just slightly smaller than the compartment. The tank will be about 57 litres.

Jianyang was right when he said it's dangerous to drill holes on the sides. The boss confirmed that the coils are on all sides. So I have no choice but to drill the 2 holes on the cover. But the freezer's cover is such that it isn't very air-tight and it sorts of flips over. Here's a pic:



Melvyn suggested we improvise a new cover ourselves using plastic. We went shopping for the necessary items but haven't got round to buying the piece of plastic yet. Anyway, I went to a shop around King George's Road where they have all sort of hoses for sale. I asked and one whole reel of PVC tubing, 50 metres long, internal width 9 mm and 1 mm thick is only $10.50. Heck, so I bought the whole reel. Here's a pic:



I did some calculations and found that if I can submerge the whole 50 metres of this PVC hose, the volume of water inside the hose at any one time would be about 13 litres. Hmm, that seems a bit too low compared to my tank which is about 380 litres. 

The shop whom I ordered the tank from said it won't be ready until next week. That's a bummer as I was hoping to rig everything up by Sunday. Well, no choice but to be patient.

Loh K L

----------


## RonWill

> Here's a picture of the freezer I bought today


Kwek Leong, guess who's the best person to hold an "ice-cream party"!  :Laughing:  

For the tank-within-the-freezer idea, I think it's your safest bet but don't forget the polyfoam at the base of the tank. Not wise to stress the freezer's base from uneven weight distribution.

If the tubing isn't long enough, just get another roll and connect it up. No fear about leak since it's all within a customized tank.

One thing you missed out... what options do you have for temp adjustment/tweaking?? [ain't cool to have to wipe condensation, just to see the fishes!]

----------


## FC

KL,
How much power is this fridge rated? I suspect your tank's size would required at least 100 watts model.

----------


## timebomb

> One thing you missed out... what options do you have for temp adjustment/tweaking??


Ronnie,

I forgot to mention that but yes, the freezer comes with a thermostat and there's a dial for setting the temperature. It has 5 settings, from cold to very very cold. I couldn't find the specs though so I can't tell you the wattage. But the boss said it's very low. I suppose it should be about 75 watts or lower.

Guys, if you like the freezer idea, I can give you the contact to the boss of Potong ice-cream. I asked and the boss said he wouldn't mind but he does not want his contact number to be pasted all over the world wide web as he's not in the business of selling freezers but ice-cream. I can't promise he will quote you the same price though but you can private message me for his number if you're interested.

The other thing I've found out, if you're looking for a bar fridge, the ones at Mustapha and Gain City seem to be cheaper. Someone told me that along Jalan Kayu, where the famous roti-prata is located, there are some stores there dealing in second-hand refrigerators. You may want to check them out.

Loh K L

----------


## timebomb

Hi, fellas,

Today, I did some cosmetic work on the second-hand freezer I bought. This is how it looked before my wife and I started working on it.



This is how it looks now:



Nice?

I should have chosen another colour but it's too late to do anything about that now  :Crying:  I didn't paint the freezer; I used Oyama paper which can be quite a job if you're not familiar working with it. Oyama paper costs quite a fair bit if you buy it from the fish shops but from the wholesaler, it's pretty cheap.

Here's the address:

Teck Seng Enterprises (21) Pte Ltd
14 Kaki Bukit Place
Singapore 416192
Tel: 67423035

They have all sorts of Oyama paper for sale and the prices range from between $4 to $6 a metre. The paper is of width 1 metre, I think. They also sell all sorts of tape - Duct tape, Scotch tape, Electrical tape etc. Name the tape and they have it. But no video tapes though  :Laughing: 

Loh K L

----------


## gweesm1

Hi Loh,

Nice looking freezer!!! I wonder if it is leak proof, if it is, and there isnt any electronic device/control in the freezer, I think you can start filling the freezer with water and get it to work.  :Smile: 

Regards,

----------


## whuntley

> Okay, fellas,
> 
> ... Anyway, I went to a shop around King George's Road where they have all sort of hoses for sale. I asked and one whole reel of PVC tubing, 50 metres long, internal width 9 mm and 1 mm thick is only $10.50. Heck, so I bought the whole reel. Here's a pic:
> 
> 
> 
> I did some calculations and found that if I can submerge the whole 50 metres of this PVC hose, the volume of water inside the hose at any one time would be about 13 litres. Hmm, that seems a bit too low compared to my tank which is about 380 litres...
> 
> Loh K L


The picture was the final incentive for me to speak up. What is being called PVC tubing is known here as clear vinyl tubing, and it is dramatically different from PVC rigid pipe. We routinely use it for drains, airlines and even filling tanks.

That said, it should never be used in a long-contact or repeated contact situation with water. To make it flexible, chemical plasticizers are needed in the body of the tubing. Those are somewhat toxic and can usually be ignored in air, but in intimate contact with water, for a long time, they will gradually dissolve to the detriment of your tank's inhabitants.

There is a huge difference between a one-pass use as airline or fill tube, and long-term contact with the tank water. Ask someone who knows hospital procedures why they are outlawed for any major patient-contact applications. OK? There, all oxygen lines, etc. are silicone based. Only brief contact applications, like IV tubing is ever vinyl, AFAIK.

I could be all wet on this, but don't think so. I'd rather be embarrassed like mad  :Opps:  than have you do something potentially harmful to your tank's inhabitants. [I'm even less anal about copper and aluminum tubing than I am about organic plasticizers. ]

Wright

----------


## TyroneGenade

Even if one ignores the possible effects that the chemicals may have on the health and fertility of your fish the fact remains that plastic has very poor heat exchange properties... I would of thought Wright being the engineer may of caught on to this.

I wish I could suggest an alterantive but I can't. Why not get an airconditioner and then everyone can enjoy the cool experiance?

----------


## timebomb

Wright,

When I bought the PVC hose, I asked and the guy at the shop showed me another type of hose called PU. I don't know if PU is the same as polyethylene but I kind of suspect it is. I offered to buy the PU hose but the guy said it's not suitable for fish tanks as over time, it will melt if it's in contact with water for too long. I'm quite sure the guy wasn't pulling my leg or something as the PU hose costs 4 times more than PVC. He would surely have made a bigger profit if I bought the PU.

Tyrone,

The reason we don't use air-conditioning is simply because it can be very expensive. Some would already consider it extravagant to have air-conditioning for humans, much less fish. I have air-conditioning in all 3 bedrooms in my house but the main tank is in the living room and it would cost me big bucks to air-con that room. 

Loh K L

----------


## ruyle

KL, is there a distinctive fragrance to this hose? Does it get its name for
content, or reputation?  :Laughing:

----------


## timebomb

> Hi Loh, Nice looking freezer!!!


Well, well, look who's here. Where have you been, my young friend. We miss you.

The freezer isn't leak-proof so I'm going to use a tank to hold the water. I collected the tank yesterday from the fish shop. It's about 57 litres. As for temperature control, there's a knob for setting it. I'll show the pictures later. Melvyn is coming over this afternoon to help me rig everything up. You're welcomed to drop over if you're interested. And so is Gan and everyone else who wants to see if the DIY chiller is going to work. 

Loh K L

----------


## stormhawk

PU stands for Polyurethane. Different in properties from PE, Polyethylene.

----------


## stormhawk

An article on the use of the pthalate-group of plasticizers in the making of PVC products, like hoses. 

http://www.mercola.com/2000/dec/24/plasticizers.htm

----------


## stormhawk

Having studied polymers during my polytechnic days, I would not recommend the use of cheap hoses as some of these are made with some toxic plasticizers like the phtalates. If anything's safe I'd go with Eheim hoses or any hose made for aquarium use. Nothing beats using something that is trusted by many people worldwide.

----------


## ruyle

Jian Yang, that's pretty dazzling! Thanks for the bouquet of hoses!  :Laughing:  As an experiment say "phtalates" standing close to a mirror....be honest now,
did the mirror get wet?  :Laughing:

----------


## ruyle

Hummmm, then polypropylene is probably "PP" right?  :Surprised:

----------


## stormhawk

Yup. That's right. The plastics have a numbering system. Look for the triangular recycling symbol on the bodies of the plastics and there will be a number in the middle of the symbol. That denotes the plastic material.

KL, if its possible, try to get food-grade PVC tubing. These are non-toxic and safe for aquarium applications I think.

Here's a website of a Canadian manufacturer of food-grade and aquarium-safe plastics.

Dynamic Aqua-Supply Ltd.

----------


## ruyle

> http://www.mercola.com/2000/dec/24/plasticizers.htm


Very sobering indeed, especially the link to the IV bags which are universally used in US hospitals!

----------


## stormhawk

Bill, there's an even more sobering article on the US FDA's website on the presence of these toxic plasticizers in healthcare applications. Can't recall the link but its there alright. Tells you about every healthcare product that has these plasticizers in their materials.

----------


## ruyle

> KL, if its possible, try to get food-grade PVC tubing. These are non-toxic and safe for aquarium applications I think.


So sayeth the big guys over here: ours in the states are milky white, stiff
(from lack of plasticizers) but can be bent to your will if first placed in boiling water. Costs more, too :wink:

----------


## ruyle

> Bill, there's an even more sobering article on the US FDA's website on the presence of these toxic plasticizers in healthcare applications. Can't recall the link but its there alright. Tells you about every healthcare product that has these plasticizers in their materials.


Jian Yang, thanks, I'll check on it in the morning. It'd keep me up all night!  :Think:

----------


## timebomb

Thanks for the info, Jianyang. But I have to confess I'm confused with all these plastics called PU, PE etc.

After all, I'm supposed to be the guinea pig, right? If my fish die, I'll let you all know immediately but I have no intention of throwing away a perfectly brand new reel of hose I just bought. It didn't kill James' Guppies when he was using it but it could be it takes time for the poison to spread. I don't know but I be happy to use food grade plastics if I know where I can get them. Buying from Canada is out of the question as I need it now.

Loh K L

----------


## stormhawk

KL, I know about the confusing bit. I was just as confused as you are when I was studying it and I'm still confused even now. I have to admit my knowledge of polymers has deteriorated since I enlisted for NS.  :Opps:  

Anyway, I think the shop where you bought the hose from should know which plastics are food grade and suitable for aquarium use.

----------


## timebomb

> Anyway, I think the shop where you bought the hose from should know which plastics are food grade and suitable for aquarium use.


Well, I certainly hope so, Jianyang.

Folks, I have good and bad news. First, the good - the DIY chiller/freezer is up and running. Many thanks to Melvyn Seah and Deric Ong, my 2 close buddies. They did all the work. I took the photographs. Here's a pic:



As you can see, Melvyn and Deric did a pretty good job with the cover and the hoses. The DIY chiller looks neat although my balcony is in a mess. I made some changes to the original plan. Instead of using one external cannister filter, I'm using 2. One to pump the water into the freezer and the other to pump it back into the tank. We tried using one filter but it wasn't strong enough to pump water through 50 metres of PVC hosing. I didn't put in a powerhead and neither did I use an airstone to circulate the water in the chiller. There's a chance the water inside the chiller may freeze but I will be monitoring closely over the next few days.

Here's a pic of the tank inside the chiller with the 50 metre hose:



The hose later started to kink when we fillled it with water. So we decided to loop it lying down instead. Here's a pic of how it is rigged up under the cover:



Okay, that's the good news. Now for the bad.

After the chiller was switched on, I put in a new digital thermometer into my fish tank. The old one went kaput several months ago but I didn't replace it until this evening. The thermometer registered a shockingly low temperature of 26.6 degrees Centigrade  :Shocked: . 



But it was raining this afternoon so that's perfectly understandable. The 3 cooling fans I was using are pretty effective, I must say. It just makes me wonder if the DIY chiller is worth all the trouble. Anyway, at or about 5 pm, after the chiller was switched on and the fans switched off, the thermometer registered 26.6 C. One hour later, it went up to 27.6 C. Shucks, maybe I should stick with the fans instead  :d'oh!:  

But it's too early to tell, I suppose. Maybe I'll wake up tomorrow morning to find the tank has turned into a block of ice  :Laughing: 

Loh K L

----------


## PohSan

Hi KL,
I believe that one hour is not enough to bring the water temperature down and I think you have not set the freezer to the coolest setting yet. I am quite confident that this DIY chiller should work. 

I am game to build one but that will be later part of the year after I have completed my fish rack and some of my major jobs' project.  :Opps:  

Regards,
Ong Poh San

----------


## whuntley

> Originally Posted by stormhawk
> 
> Anyway, I think the shop where you bought the hose from should know which plastics are food grade and suitable for aquarium use.
> 
> 
> Well, I certainly hope so, Jianyang.


Sounding like a crank, again, but this is *not* something I would expect them to know. Using such tubing for very short runs, and for filling and drains, doesn't provide the exposure you are causing here, so they have no good reference points or experience to give you good advice. 

Someone also pointed out that I should have commented on the poor thermal properties of your hose. [Mea culpa!] 

It is awful, and I'm surprised you added a second pump to the system. With PVC, you need very, very slow flow if you want much chilling effect, I suspect. Using one pump and throttling it down might increase efficiency a little bit. Rapid flow and two cannisters is probably *adding* almost as much heat as the system can pump out. What is the Watt rating of the freezer and the two cannisters? The former must be several times the sum of the latter two, to have much "impact." :-) This ignores other heat sources like lamps and other devices. 

It sure is fun to kibbitz all the way from CA. That's a mighty big ocean to come across and kick my backside for being a troublemaker. :-) 

As a first cut at getting some efficiency (without doing the numbers) I would set the freezer to max cooling, and then throttle the water flow down until the outlet water was about half way between the inlet temp. and the temp. of the water in the chiller sump tank. From there, regulate the outlet temp. only by resetting the thermostat to where you want the cooling to be. That flow rate should be a fairly efficient one, based on the poor conductivity of the tubing and the capacity of the freezer, as reduced by the pump heating. 

"Doing the numbers" reminds me of my "Scotch and Water Diet." [I'd use BTUs for you empire addicts, but as an engineer I am more comfortable with metric units.  :Smile:  ]

A shot of scotch whiskey contains 75 calories. 

Fill a tall glass with water and melting ice. Say it is 200 cc at zero degrees C. Add the scotch. 

Your body must gain energy from the 75 calories in the scotch, but it has to heat the 200 cc up to 37C before it is expelled. At the definition of the calorie as the energy to heat one gram (1cc) of water one degree Celsius, that means your body must give up 200X37 calories (7400) while taking in only 75 calories.

Bottom line is that every tall scotch and water you drink reduces your calorie intake by 7325 calories. That beats the heck out of a lot of stupid aerobic exercise! [Where's that tongue-in-cheek emoticon?  :Smile: ]

After working your way through the diet exercise, does anyone want me to do any calculations on the chiller?  :Laughing:  

Wright

----------


## TyroneGenade

Diet Calories are not the same as physics Calories... I think there is a 1000 difference so you are actually taking in 75 000 calories of Scotch... but this also don't sound right so just ignore that bit...

I have thought long an hard on the issue of the poor thermal properties of the hose and how to efficiently cool your tank. My solution goes as follows:

Construct a thin glas tank (a chiller-tank) about 20 mm x (height of your tank - 10%) x (lenght of your tank - 10%). Drill two holes into the top of the tank and silcone good PVC fittings into the holes so you can slip your hose over it. The chiler-tank must be water tight for this to work by the way. Then pump the water from the freezer through the chiller-tank that is now suspended in the main tank. Glas has much better thermal properties than the plastic hose and should serve a much better chiling effect. You may not need a very tall or long chiller-tank because glass is an excellent heat exchanger (compared to plastic)! Some experimentation will be needed.

The best option is perhaps stainless-steel tubing that is hung in the tank and water pumped through it. I would still use the plastic hose as a go-between the freezer and stainless-steal tubing.

This is just my 2c. I'm a biochemist not engineer.

Cheerio

----------


## RonWill

> Instead of using one external cannister filter, I'm using 2. One to pump the water into the freezer and the other to pump it back into the tank


 What's the point of that? Heat from the 1st pump is displaced within the freezer, only to be heated up by the 2nd canister pump. All motors displaces heat, be it mounted above the canister or within the sump.

I'm puzzled why you'd want a 'strong enough' flow, when it's the flow of water through the hose, while it's in the freezer, that makes the difference. In page 2 of the thread, I've already said, "_Similar to concepts that apply to UV sterilization, it's the duration of exposure and flow-rate within the unit that makes it effective._"




> The hose later started to kink when we fillled it with water. So we decided to loop it lying down instead.


 I believe it would have been better if you've just taken enough length from both ends for the connection and left the rest intact, ie. without loosening the coil. Since the tank is filled with water, the weight of the water within the coil doesn't make much difference, not significant enough to kink the hose, I think.




> The thermometer registered a shockingly low temperature of 26.6 degrees Centigrade


 Did you have another thermometer for reference?

You'll need some time to tweak the freezer's setting but for a start, set it midway, instead of the coldest setting... it'll be interesting to see your fishes in thermal undies!  :Laughing:

----------


## whuntley

> Diet Calories are not the same as physics Calories... I think there is a 1000 difference so you are actually taking in 75 000 calories of Scotch... but this also don't sound right so just ignore that bit...


Tyrone,

You sure know how to take all the fun out of another ridiculous diet.  :Smile: 

Food calories are heat-of-combustion calories, and those are, by tradition, kilogram calories. You are correct that the difference is exactly 1000 and the net caloric intake is 75,000 minus the 7400 (in gram calories).

Switching back to Martinis, since my scotch diet is about as useful as a low-carb diet.  :Smile: 

Wright

----------


## ruyle

KL, where did you get the nice bulkhead fittings on the lid? Love the color of the box! My next car will be that color!  :Laughing:  Actually, I'm serious  ::smt037:  My question is: if you throttle down using just one pump, would the water have a better chance to interact with whatever plasticizers are in the hose? Or is it decreased by having less water pumped per minute?  :Think:  I hope you keep us posted for more chilling episodes!  :Laughing:

----------


## timebomb

I woke up this morning at 6 am expecting to see a block of ice but the thermometer read 26.5 C. Shucks. I checked the freezer and it was pretty warm on all sides on the outside. I checked the water inside the tank inside the freezer and heck, it isn't even cold although there's a lot of ice on the walls of the freezer.

At about noon, I called home and my maid said the thermometer read 25.9 C. Whoopeee!!! I thought. It's working!!!! Considering that its pretty hot today and the fact that the fans are no longer running, 25.9 would be pretty good.

Thanks for all the suggestions, folks. I'll answer your questions when I have more time but for the moment, I will just explain why I'm using 2 filters. One external cannister filter alone can't pump the water through 50 metres of hose. We tried but it won't work. Even with 2 filters, the flow rate is just slightly better than a trickle. 

I thought about the chiller when I'm at work and I think I know what's wrong. I should have chilled the water inside the freezer first before pumping the water from the tank through the hose. Currently, what's happening is my freezer has to chill not just the water inside the chiller tank but the fish tank as well. That would mean chilling more than 400 litres of water. The reason the water inside the chiller isn't cold is because the temperature would be about the same or equal to the temperature of the water inside my fish tank. Although they seem to be 2 entities, the water inside the chiller tank and the water inside my fish tank is actually one because they are related to each other by the hose which runs from the fish tank, through the freezer and back into the tank again. I hope you all understand what I'm trying to say. Frankly, I'm just as confused myself.

But this is what I'm going to do.

It's about 4.30 pm now and right after I send this post, I will switch off my filters. In other words, I will let the freezer chill the water inside the chiller tank first. When it's pretty cold, close to freezing, I will run the filters and let the water from my fish tank flow through the hose. It should chill the water in my tank faster this way. If it doesn't, well, then it's back to the drawing board again.

Loh K L

----------


## timebomb

Okay, folks, the filters have been switched off. It's now 4.32 pm. The thermometer reads 26.0 C. I expect the temperature of my fish tank to climb. It has to get worse before it gets better  :Laughing:  

I checked the temperature of the water inside the chiller tank and it's 24.0 C, just slightly below that of my fish tank. I expect it to go much lower very soon, now that the filters are off. 

Loh K L

----------


## RonWill

> Okay, folks, the filters have been switched off. It's now 4.32 pm. The thermometer reads 26.0 C. I expect the temperature of my fish tank to climb. It has to get worse before it gets better  
> 
> I checked the temperature of the water inside the chiller tank and it's 24.0 C, just slightly below that of my fish tank


Kwek Leong,
I think if you have another digital thermometer, better if it's the same model as what you're using now, you wouldn't have to open the freezer's lid to check the temp and lose lotsa 'cold' air.

Before you fit it to the freezer, verify/compare the readings, just so you know how far off each unit differ.

To help speed up the cooling water in the freezer, drop in a bag of ice from 7-Eleven.

Seriously, I can't imagine an Eheim canister not able to push water through a coil of hose. Either you have a kink in there somewhere or possibly something obstructing the flow (clogged filter media perhaps?). Switching off both canisters sorta defeats the purpose of the whole exercise, I think.

If James can do it with a measly bar fridge, I can't see why your freezer wouldn't work!  :Confused:

----------


## timebomb

> If James can do it with a measly bar fridge, I can't see why your freezer wouldn't work!


Hah!! It will work, my friend but it's going to take a longer time, that's all. 

I was just as puzzled too when one Eheim 2215 couldn't push the water through 50 metres of hose but I didn't have time to check everything yesterday. To check if the problem laid with the filter media would mean emptying out the filter which I was reluctant to do. The problem, I suspect, lies in the diameter of the PVC hose I'm using. It's slightly smaller than an Eheim hose which would mean the volume of water travelling through the hose isn't constant. For the Eheims to work effectively, the hoses should be of the same diameter but I couldn't find a PVC hose that's of the same size. 

As for the thermometers I'm using, they could be off but it isn't much. I checked the digital one against 2 analog thermometers and the difference was about only half a degree C. It's 8.15 pm now and I just checked the water inside the chiller tank. The temperature there is now 
15 C. Brrrr, it's cold. And I think that proves what I suspected. 

To chill the fish tank, I have to chill the chiller tank first. The theory is that whilst the freezer is chilling the chiller tank, the fish tank is warming it up. The fish tank is much bigger so although the freezer is effective, it will take a long time to balance out the temperature in both tanks. It will work but it's going to take a longer time, that's all. 

The filters won't be switched off forever. When the temperature in the chiller tank drops to about 10 C, I will start the filters working again. My fish tank is still about 26.5 C now but that's because I cheated. When I switched off the filters just now, I started the fans working again  :Laughing:  

Loh K L

----------


## timebomb

> KL, where did you get the nice bulkhead fittings on the lid?


Bill, are you referring to these fittings? 



They're cheap and easily available in hardware shops. If you can't find them in the US of A, let me know and I'll send some to you. As for the Singaporeans following this thread, here's the address of the shop:

Chuan Hup Huat
Block 809 French Road
#01-184
Kitchener Complex
Singapore 200809

Melvyn bought the fittings for me. He made the mistake of not buying the washers as well so the thing leaked when we started the water running. Make sure you pick up 3 washers for every coupling. It looks completely water-tight but it isn't so without the washers. The same shop also sell all sorts of hoses. It's where I got the PVC hose.

Loh K L

----------


## timebomb

> I have thought long an hard on the issue of the poor thermal properties of the hose and how to efficiently cool your tank.


Tyrone, thanks for the tips but I'm afraid it's too late to rig up a chiller tank like the one you described. The one I'm using now is just slightly smaller than the freezer's compartment. It's about 57 litres. Here's a pic:



Poh San who called me on the phone this afternoon suggested something which he calls thermal plates. I have no idea what Poh San intends to do but he said he's going to show me the diagrams later. He said it will help to chill the water inside the hose effectively.

Loh K L

----------


## timebomb

> What is the Watt rating of the freezer and the two cannisters?


Wright, I don't know what's the watt rating of the freezer as the specs don't specify that. I tried to check the rating on my Eheims too but the words are all worned out. The numbers aren't visible anymore.

In any case, I doubt the heat generated by 2 Eheims can be high enough to neutralise the chilling effect of a freezer. I know nuts about electricity but hey, the freezer's a lot bigger  :Laughing: .

As for the conductivity of the PVC hose, I'm aware it isn't as good as aluminium or anything made out of metal but we have to be wary of the costs too. If I have to buy hose from Canada or use something made of metal, the costs may become so high I might as well just buy a chiller.

Loh K L

----------


## RonWill

> To check if the problem laid with the filter media would mean emptying out the filter which I was reluctant to do


2215
for tank size up to 350L
Pump output 620L/Hr
Filter circulation 510L/H
Delivery head 1,80 M/WS (water column) 
Filter volume 4L

Kwek Leong, I have a 1048 at the lab that you can borrow. It's output is rated slightly lower than your 2215 but if the 1048 can do the job, I think the bottleneck is obvious.

1048 Centrifugal pump 
Pump output 600 L/H (158 U.S. Gal/H)
Delivery head 1,50 M/Wat.Col. 4 ft. 11 in./Wat.Col. 
Power consumption 10 W 
Hose connection (suction side) Ø13mm (1/2") 
Hose connection (pressure side) Ø13mm (1/2") 

I don't think the slightly smaller hose diameter is the culprit. Let me know if you want to pick up the pump.

----------


## timebomb

> I don't think the slightly smaller hose diameter is the culprit. Let me know if you want to pick up the pump.


Ronnie, thanks for the offer but I started the filters just now and guess what. I switched on the first filter and it was enough to push the water all the way back into the tank. I guess when we rig the thing up yesterday, there wasn't enough water in the hose for the thing to work properly. So you're right about the diameter of the hose not being the culprit.

The temperature inside the chiller tank read 12 C when I started the filter working again. The fish tank is 26.9 C at about 10.20 pm. Let's see how it goes tomorrow morning.

Loh K L

----------


## timebomb

I know this sounds incredible but right after I sent the last post, I checked again and the temperature of my fish tank has dropped to 25.5 C. A drop of more than 1 degree in a matter of less than 10 minutes. Wow!! 

Loh K L

----------


## ruyle

KL, I've never seen anything like the black and red ball valve or the bulkhead ones in Home Depot or Lowes. I'll look again...as a sidebar,
how's the American hornwort doing? It would like this cooler tank  :Very Happy:  
If you want some more, let me know!

----------


## timebomb

Bill, the black and red valves are for stopping the flow of water. I think Eheim have something similar but those I bought are much cheaper. As for the American Hornwort, they're all mixed up with the Singapore ones. I'll try and grow some of it in my tank later.

By the way, folks, taaaa.......daaaaaaaaaaa.........

It's about 11 pm now, about slightly more than half an hour after I switched on the filter. And the temperature in my fish tank is an amazing 25.0 C. Take a look:



Loh K L

----------


## TyroneGenade

If one could rig such a setup for several tanks as part of the central filtration setup one could well be able to keep a range of cool water killies without having to resort to expensice air conditioning. I'm certainly giving it a lot of thought for when I return to South Africa in year or three's time. Maybe I can start mass producing cool water Aphyosemion as well as Nothos...

tt4n

----------


## FC

KL,

As discussed the last time we met, you should let the long hoses do the water flow via gravity (like siphon) and place the filter/pump after the freezer and just before the tank. Only this way will you put the pump to effective use. Your initial problem with the flow was probably that the hoses were not bleeded (or has air pockets) which is the devil for any water pump. The 2nd filter should be use as normal filtration use, as decided.

You should try to fill the gaps between the chill tank and the freezer walls with conductive material. I am yet to find something suitable, some kind of stainless steel wool would be great. Did you fill the tank with enough water to cover the hoses completely? Fill up to near the tank's top would be idea if the freezer can take the punishment.

Ronnie's idea of using the ice bags were good to kick start the fellow.

----------


## PohSan

I called up KL in the morning to suggest a thermal plate to replace the lengthy hose. This is not a new idea as it is widely used in water heater and maybe commercial chiller

The drawing of the thermal plate is as follows:

3D View:

Thermal plate has walls inside the plate so that water will flows in a zipzap manner. It will maximize the tank water contact with the cool water, which is isolated. The distance between walls and the depth of the "drain" will depends on the flow rate of the pump in order to prevent freezing inside the plate,

There is hose connector on the left side of the plate as indicated by the green arrow. The line in blue is actually rubber sealer to prevent leakage. 

Top View:


This is a top view to show water flow. It is possible to have more walls inside as it will improve the efficiency. Alternatively, I can connected up many plates in series to improve the efficiency as well.

Later when I show the drawing to one of my friends. He quoted that such a plate will not be cheap and it will be much cheaper to use hose as a media to transfer heat. However, I will try to make one and test it on my DIY chiller if possible.

Regards,
Ong Poh San

----------


## ruyle

I hope all this material will be archived safely. I will want to build my own
DIY chiller when I move to Thailand. Imagine, Diapterons in a tropical
zone and all the plants that like the low-mid 70sF!  :Surprised:

----------


## RonWill

> KL, I've never seen anything like the black and red ball valve or the bulkhead ones in Home Depot or Lowes


Bill, if you're looking for barbed 1/2" ballvalves, look here;
http://dripirrigation.com/index.php?cPath=35_50

----------


## ruyle

Wow, thanks for the site, Ronnie! I have some of the 1/4" microball valves
made in Australia but not at this price! They ship overseas, right?

----------


## RonWill

> They ship overseas, right?


Huh? 

Bill, this is the business address of the link... ship overseas to where? Alabama  :Question:  :wink: 
The Drip Store
1145 Linda Vista Drive, Ste. 108
San Marcos, CA 92069
Tel: 760 682-1580 Fax: 760 682-1585
Business Hours (9 AM - 5 PM Pacific Time)

If you're using nickel-plated gang-valve for BBS hatchery, I suggest you order the inline taps as well (mentioned in this post)

Kwek Leong, glad to know the water is flowing now. With 620L/H output and better Max.Head than the 1048, the 2215 can't be a let-down.

Let's see what the thermo reads in the morning. BTW, where did you get that digi-thermo? Good for half-blind eyes!  :Laughing:

----------


## ruyle

> Bill, this is the business address of the link... ship overseas to where? Alabama  :wink:


Umm, no, Ronnie, do they ship overseas to SG and Thailand to be exact?  ::smt027:  I imagine they would ship INCONUS :wink:

----------


## RonWill

> Umm, no, Ronnie, do they ship overseas to SG and Thailand to be exact?


Bill,
It was Kho (our administrator) who gave me the link. We're gonna order their drip irrigation system for our plants and yes, they do ship to SG and I suppose Thailand as well. [I know what you meant. Being tired at work doesn't mean I'm that dense :wink: ]

----------


## ReDDeviLs

hi there, is this DIY project able to chill a 150Gallon tank?

----------


## ruyle

> Being tired at work doesn't mean I'm that dense :wink: ]


I knew it was either a low biorhythm or you were pulling my leg!  :Laughing:  Get
some rest when you can! I think back on 20 years of navy medicine and
all the sleep deprivation, thank gawd I am no longer in it!

----------


## FC

ReDDeviLs,
Welcome to Killies.com!

We are glad to share our knowledge with anyone but we would bias towards those who make an effort to sign off (at the end of the message with their name).

If possible, in your registration, give us some basic/minimum introduction of yourself like the estate you live in. Here in Killies.com, we like to make friends and talk to someone who care to review a little about themselve. It's like meeting a stranger on the street, you introduce yourself first before any conversation, right? Any further info is not important but welcome.

We meant to build good ties and respect among forumers , youself included, here and I think it has to begin with, my name is.... 
I hope you would appreciate what we are trying to accomplish here.

----------


## turaco

KL, you might consider insulating the hose outside the chiller with those black air-con insulation foam(tube-like with a hole in the center). Can get from air-con shop. Try to shorten the length of the hose outside the chiller to prevent precious cold air lost. Maybe placing the filter on top of the chiller? Oh, come to think of it, you need to insulate your filter as well  :Laughing:  .

----------


## gweesm1

> Well, well, look who's here. Where have you been, my young friend. We miss you.


I have been busy lately. The Construction Industry is really bad, and my company had been picking up a lot of tenders, so which means late night.. Anyway I had re-setup 4 small planted tanks.




> You're welcomed to drop over if you're interested


Thanks! I will drop by next month when I am not so tie down by tenders. (I hope)




> KL, you might consider insulating the hose outside the chiller with those black air-con insulation foam(tube-like with a hole in the center). Can get from air-con shop. Try to shorten the length of the hose outside the chiller to prevent precious cold air lost. Maybe placing the filter on top of the chiller? Oh, come to think of it, you need to insulate your filter as well  .


Good idea. Plumber use these on copper pipes to prevent water from losing heat from the heater to the tap point.

regards

----------


## timebomb

Hi, fellas,

I woke up this morning to see 24.4 C. Frankly, I was a bit disappointed. I was hoping it would be lower. My maid who was instructed to check on the thermometer periodically said the temp hovered between 24 and 25 for most of the day. I came home in the evening and saw 24.0 C



It seems there's a psychological barrier or something. The thermometer simply refused to go below 24. Maybe it doesn't like it that cold  :Laughing:  Anyway, I checked and the temperature of the chiller tank has gone up to 22.5 C, just slightly lower than that of my fish tank. 

I think Poh San's idea of using thermal plates could be very effective, especially when they are used in a mini bar fridge. As for Gan's suggestion to wrap the hoses with insulation foam, I will definitely try it. 

I think it could take a while before I see temperatures lower than 24. After spending about Sing $250, I won't be happy until I see 22 C. Ronnie warned me that condensation on the glass could be quite a hassle but if it should happen, the next project would naturally be DIY wipers  :Laughing: 

Loh K L

----------


## TyroneGenade

Given that the ambient room temp is about 30°C I think 24°C is quite an achievement. You should be very impressed. I didn't think you would get near there with the plastic pipes you were using.  :Opps:  

Well done! I will be pirating your design back in SA so I can keep Diapteron!

Ciao

----------


## FC

> It seems there's a psychological barrier or something. The thermometer simply refused to go below 24.


  :Laughing:   :Laughing:  Not the thermometer, it's you! Start believing and you'll see it comes... I guess it would bottoms out at 23 degree celcius at best.

----------


## whuntley

For those next couple of degrees, here's something you can try for no great cost.

Right now, you are getting a lot of insulation from the air around your glass sump. [Measure the difference between freezer wall temp. and the water temp.] Try stuffing paper or rags down between the freezer walls and the glass, then wetting them to get better thermal contact between the freezer and the glass. If that works, you may want to consider buying pads of open-cell foam to perform the same function, and rig a sump to keep it wet/frozen.

I was not clear on why the freezer cannot be made to hold water. Even if only up to the thermostat, water would be a lot better heat conductor than air, I suspect.

You might also see if efficiency improves by blowing some air over the warmest parts of the outside of the freezer case. Finned aluminum heat-sink material is often available at electronics surplus houses. Some fins attached to the outside of the hot case could make a big difference, if the fins are oriented so air flows up through them by convection (slots vertical).

Planning a heat-pump system is a bit like a flowing water system. You need to look for any thing that is slowing or obstructing flow, anything that is diverting energy where it isn't wanted, and take appropriate measures to fix each of them. [You guys are taking me way back to my undergraduate courses in thermodynamics and fluids.  :Smile: ]

Wright

----------


## TyroneGenade

My physics lecture (Prof Koen, there is a constant named after him so his opinon must we worth something...) was of the opinon that still air is the best insulator. Filling that void between the tank and freezer is in my humble opinon very important. I don't know about using wet anything as it may freeze and crack the glass... maybe steal wool?

Ciao

----------


## whuntley

You need the wet for thermal conductivity. Steel wool or dry newsprint, etc. will just keep air from circulating and make things worse (assure the air is more still).

If a rag or wet paper freezes, it's not likely to crack the glass, as it will freeze near the freezer wall, first. Monitor, of course. You'll have to reduce the freezer setting before freezing is a really serious problem, if the thermal conductivity is really high (air is all displaced). The tank will be too cold before then.

I heard stainless steel mentioned here, a while back. If you want thermal conductivity, it is terrible. Barely better than clear vinyl. Copper and aluminum are far, far better for heat transfer. Ever notice how warm stainless feels compared to other metals? It is because it has rather poor thermal conductivity.

Here's another thought. Get rid of the glass tank and that surrounding air insulation. Put a large plastic garbage bag in the freezer and fill it with water. Then immerse your tubing in the bag of water. Bet you will have to turn the freezer way down to keep from overcooling your tank! Particularly true if you insulate the lines and cannister between freezer and tank.

May need to add that power head to minimize local freezing.

Wright

----------


## FC

Wright,
Brilliant idea!
Below are the scenarios that ran through my mind on what would happen to the Wet Paper Pulp (Pulp), the chill tank's Glass Wall (Glass) and the Freezer Wall (Wall):
1) Pulp begins to freeze at/near the Wall, slowly propagating towards the Glass;
2) heat from the Glass (easily more than 10 degree Celsius) travels to the Pulp, melting any froze from on the Pulp near the Glass;
3) repeat
In a nutshell, the Pulp will only freeze at the Wall and never at the Glass. Thus, improving the cooling efficiency without the danger of breaking the glass.

----------


## FC

For those who may be puzzled why I said:
_"heat from the Glass (easily more than 10 degree Celsius) travels to the Pulp, melting any froze from on the Pulp near the Glass"_
And not the "cold" from the Pulp travel to the Glass (thereby cooling the chill tank).
This is because scientifically, hot always travels towards the cold and not/never the other way round.

----------


## whuntley

Freddy,

It depends on your source. What you say is true if the heat source is warmth, but what direction is the propagation when you start with coolth?  :Smile: 

Wright

----------


## FC

Wright,
You caught me. :P 
However, as we are trying to remove heat from the tank, naturally, I would assume these:
- the Chill Tank is warmer than the Wet Paper Pulp;
- the Wet Paper Pulp is warmer than the Fridge Wall and
- the Fridge Wall is warmer than the Fridge’s Evaporator

----------


## timebomb

The temperature went up today. It hovered between 24.5 and 25.5 for most of the day.

Thanks for all the suggestions. I have to mull over them for a while before I decide what to do. I checked the tank inside the chiller and the space between the glass and the walls of the freezer is mostly caked with ice. In some places, the ice is already touching the glass but in others, there's still a small gap. It would be difficult to fill this gap with paper pulp and I don't know how I can keep them wet. 

Wright, the reason I didn't simply fill the freezer with water is because the guys who are selling them told me that freezers are not meant for holding water. It will leak and damage the compressor under the freezer. I wonder if it's a good idea to use a plastic bag instead of a glass tank to hold the water. The plastic bag is likely to leak over time unless I can find one which is pretty thick. 

I bought another digital thermometer for the chiller tank and I noticed the temperature there is always about 2 degrees lower than the fish tank. 

By the way, I noticed that the plants in my fish tank are pearling a lot more since the day I rigged up the chiller. I doubt its the lower temperature that's causing this. More likely, it's because the fans are switched off. I can't explain it but it seems like when there's less water movement ( no fans and weaker water circulation from the filters), the plants absorb light better. 

Loh K L

----------


## FC

> I checked the tank inside the chiller and the space between the glass and the walls of the freezer is mostly caked with ice.


KL,
This is not a good thing. Ice forming there will reduce the cooling efficiency of the freezer. The ice's water source is obviously from the chill tank (sign of warm travels toward cold).
My suggestions:
1) Do not be dismay, the chill tank idea can still be improve further;
2) Switch off the fridge. Let the filter continue to run;
3) The ice should melt within a day;
4) Do as what Wright suggest - pack the gap with wet paper pulp.
5) Monitor for 3~5 days.

----------


## PeterGwee

> By the way, I noticed that the plants in my fish tank are pearling a lot more since the day I rigged up the chiller. I doubt its the lower temperature that's causing this. More likely, it's because the fans are switched off. I can't explain it but it seems like when there's less water movement ( no fans and weaker water circulation from the filters), the plants absorb light better.


Loh, its the availability of more CO2 to the plants that is causing the increase in pearling. Colder water holds more O2 and CO2....The lack of surface movement through the removal of the fans help to keep the CO2 in better but is generally not a good practice. Its fine if the plants are doing well and producing loads of O2 for the critters but if things go south due to the user not keeping up on the CO2 or nutrients, you are going to have possible O2 issues and gasping fishes. Better to lose some CO2 then a fish.

Regards
Peter Gwee :wink:

----------


## elmike

Sigh  :Sad:  

Theres only so much a low-maintenance guy needs to know. 

But this sure looks like a big thing. I wonder if an innovation of such a scale and nature comes under any HDB regulations? I dont know if anyone has raised the question before, but delving into electrical circuits to rig up an equipment such a coolant, which is no simple contraption, is no small matter to me. 

In a closely-knit HDB context, what we do has a direct impact on our neighbours. If your floor is flooded, water seeps through to the neighbours unit downstairs. And if a fire breaks out, it could spread quickly to the neighbouring units. In the wake of the 26 fire breakouts from the use of poor-quality overhead filters not too long ago, the HDB may be training their eye on the aquarium hobby. 

It pays to be circumspect and ask ourselves if everyone could duplicate the design successfully through knowledge gleaned from online discussions, although the originators design had proved to be workable and reliable. Someone must be accorded due credit, or otherwise... It's now in public domain.

Just a thought.

----------


## timebomb

> I wonder if an innovation of such a scale and nature comes under any HDB regulations?


Mike, you worry too much. 

Hey, it's just a freezer. Other than having 2 holes drilled on its cover, it's not much different from the fridge you have in your house. As for having an impact on the neighbours, a freezer/chiller definitely has less impact that a karaoke hi-fi system. It can be hell when your neighbour is a karaoke fan.

Loh K L

----------


## TyroneGenade

Hello

Been giving the "stuffing" topic some thought and think you may be able to get away with a mix of (a slurry) of ice, ethanol and potassium chloride. This mix can take temps down to -18°C without freezing. That way you can prevent the stuff between the freezer anc chiller tank freezing and cracking the latter. There are many other anti-freezes on the market that may also work. Ethanol will probably be the cheapest (and most enjoyable).

Cheerio

----------


## timebomb

Hi, everyone,

I've been mulling over your suggestions and I think I got it all cleared up in my mind now. Eureka!!  :Laughing: 

I thought about stuffing the gaps between my freezer walls and the glass of the chiller tank with pulp. I thought about using a plastic bag instead of a glass tank to hold the water. I thought about replacing the PVC hose with something that conducts heat better, something like the thermal plates which Poh San suggested.

I thought about many things but finally without even having to try them, I came to the conclusion that most of your suggestions won't work. Why, you ask? Well, the answer is rather simple but I may not be able to explain it well. But I'll try.

First, let's name the items clearly so we won't get confused. There's my *fish tank* which is about 380 litres of water. There's a *freezer* which has a certain cooling capacity. There's a *chiller tank* inside the freezer holding water, about 57 litres. There's a *PVC hose*, 50 metres long submerged in the chiller tank. There's an *external cannister filter*, used for pumping water from the freezer back into the fish tank. There are 2* filter hoses* which connect the fish tank to the chiller tank. 

Okay, suppose I replace the chiller tank with a plastic bag or do away with any sort of container altogether and simply use the compartment inside the freezer itself to hold the water. What would happen? Would a colder chiller tank translate into a colder fish tank? I think the answer is "no". Why, you ask?

Because no matter how cold the chiller tank gets, the temperature in the chiller tank and the fish tank will eventually balance out. My fish tank can only get as cold as the chiller tank. They will balance each other out because no matter how cold I can get the chiller tank to be, the fish tank will warm it up. I can get the water in my chiller tank to freeze in a short time by simply turning off the filter but what will happen when I start the filter running again? The fish tank will get cold for a while but over time, it will eventually melt the ice and warm up the chiller tank. And we'll be back to square one. The temperature of my fish tank is subjected to ambient temperature which is about 30 C on most days. With lights running 10 hours a day, the water will heat up to 33 C in the absence of cooling equipment. 

The key lies in the cooling capacity (abilities) of the freezer and the conductivity of the hose. I turned the settings of the freezer up to maximum (coldest) 2 days ago and the temperature of my fish tank has been hovering around 24 to 26 C. I've been monitoring the temperature of my chiller tank too and it's always about 2 to 3 degrees lower. It should be the same but why the discrepancy? I think it's because of several factors. First is the poor conductivity of the PVC hose. If I use something that conducts heat better, it should help in a big way. Second are the filter hoses which connect the freezer to the fish tank and the filter itself. They cause heat loss. 2 to 3 degrees is what I'm losing due to poor conductivity of PVC hose and heat loss from filter hoses and filter. If I can find a way to prevent this heat loss, I believe I can bring the temp of my fish tank down to 22 C. 

Just as an experiment, I'm going to switch on my 3 cooling fans right after I send this post. I took a look just now and the temperature of my fish tank is 25.5 C and my chiller tank is 22.7 C. Room temperature is 30.0 C. It's 7.52 pm now. Let's see how things go tomorrow.

Loh K L

----------


## timebomb

I forgot to add this:

If my theory is correct, I should wake up tomorrow morning to see a temperature of about 23 C in my fish tank. The chiller tank would be about 20 to 21 C then. The freezer can only do so much. It can cool my fish tank to a certain limit and that limit is about 24 C, I think. The cooling fans should help to bring the temp down further as it's another source of cooling power. 

That's just my theory, of course. It's all fuzzy logic; I flunked Physics when I was in school. It was one subject I hate the most. 

Loh K L

----------


## TyroneGenade

My next step would be to dispence with the chiller tank all together. Direct contact between the hose and freezer may be able to get you another degree or two. 

Then think about wrapping those return hoses in styrofoam wrap or something so they are not in contact with the 30°C air. I think you could get another 1 or 2° that way.

Remember! Simple solutions stand the most chance of success!

----------


## turaco

KL, what if, you were to disconnect the hose for perhaps a day to let the chiller run without external heat from your tank(that is, trying to freeze the water in the chiller!), link up the system again & run your filter again. It should have an upper hand to cool your tank to a lower temperature. But whether it will be able to sustain that way I'm not too sure. Beware though, a sudden drop in temperature in your tank will do a lot of harm to the inhabitants  :h:  ! By the way, what do you have in there? Guinea pigs?  ::smt003:

----------


## timebomb

> By the way, what do you have in there? Guinea pigs?


I'm the Guinea Pig, not the fish  :Laughing: 

Gan, I've already tried what you suggested. I turned off the filter the other day and within a few hours, the temp in the chiller tank dropped to about 12 C. After I turned on the filter, it went up to 22 C the next day. It's, as you have suspected, unsustainable. The chiller tank and the fish tank are linked to each other by the PVC hose and the temperature in these 2 tanks will eventually balance out, no matter what we do. To get lower temperatures in my fish tank, I either have to use a more powerful chiller or use another source. That's the reason I switched on the cooling fans just now.

Loh K L

----------


## timebomb

> My next step would be to dispence with the chiller tank all together. Direct contact between the hose and freezer may be able to get you another degree or two.


Tyrone, I don't think it would make a difference. As I've said, I can get the chiller to become very cold in a short time by switching off the filter but it won't help because the fish tank will warm it up as soon as the filter starts running. The point I've been stressing is that the chiller tank and the fish tank are not 2 entities, as I've initially thought. They are one.




> Then think about wrapping those return hoses in styrofoam wrap or something so they are not in contact with the 30°C air. I think you could get another 1 or 2° that way.


It will help but I seriously doubt we can get even one degree lower. The hoses are not very long and heat loss wouldn't be much.

Loh K L

----------


## FC

KL,
The fans will not help to bring down the temperature at this state. Remember, their performance is tied strictly to the ambient and tank water temperature differential, which is now (great enough and) greater than what the fans can do.

It is absolutely right that the chiller tank (the chill source and power) is colder than the tank (the target where the environment is heating at). Let me put it this way. If one measure the temperature of the air-con close to the louver at slow fan speed, it will read easily below 0 degree celcius so long as the compressor is kick-in. However, the room will never reach anything below 20* degree celius. Now that's 20 degree celcius (or more) different!
* - given ambient temperature above 26 degrees with typical sized air-con.

Now *how to bring the tank temperature below 24* or the room below 20 degree celius (I will not cover the room issue here)?
One got to study 2 areas:
1) the cooling target (the tank) and its' environment
2) the cooling source and its' effectiveness in heat exchange

For point 1), there is nothing much one can do to influence (nobody gonna wrap the tank with insulators). The volume of the tank is the only factor useful, for choosing the cooling equipment power.

For point 2), here is where one can do alot and you have done alot. However, the sequence should be:
1) the first one is obviously power, I mentioned:


> KL,
> How much power is this fridge rated? I suspect your tank's size would required at least 100 watts model.


From observation, yours seems to be slightly below idea but serviceable.
2) locate a cool place (all day) for planting the fridge.
3) As mentioned:


> Ronnie's idea of using the ice bags were good to kick start the fellow


4) study the method to achieve the best possible heat exchange efficiency at a given budget.
You should target nothing but all that is in the fridge.
Anything out of the fridge would not yield much return simply because the mother of all heat (from ambient) receiver is the tank and there is nothing you can do about it. The surface of hose and the filter exposed to the elements is neglible and therefore deem unworthy of any attentions.

For your situation, you are left with point 3) to do. And I beleive the possibility of bringing the tank down a degree below 24 is high. Remember the ice forming at the fridge wall is pulling down the heat exhange significantly.

----------


## whuntley

Let's go back to basics, here.

If the temperature difference between the fish tank and the chiller tank settles down to about 2 degrees, that says the flow is slow enough and the thermal conductivity of the vinyl hose is good enough to sustain that low difference. You don't need metal tubing unless you want to increase the flow rate substantially.

What about the 20 degree plus difference between the freezer walls and the chiller tank? The temperature difference, under stable equilibrium conditions, is a measure of the thermal resistance of the air gap, just as the 2 degrees measures the losses across the tube boundary (and in the external plumbing).

Tape a probe with a foam cover to the coldest wall of the freezer. If it is nearly the same as the chiller tank temp, then it isn't worth trying to fix the conductivity, there, and the freezer is working at full capacity.

Basically, you need to measure all temperature drops and get them each as low as possible. When the freezer's walls and the fish tank stabilize at nearly at the same temperature (+ a few degrees), you have reached good efficiency and only a larger freezer (or external heat-sink fins) can do any more. Any big temperature differences anywhere between freezer inner wall and fish tank represent a loss that is reducing the efficiency of the system.

Use a bit of alcohol (isopropyl rubbing alcohol is very cheap, ethanol has less aroma) to stop freezing in the freezer compartment. That was a great suggestion, for the ice is a good thermal insulator and you want none on the freezer walls to insulate the freezer's coils from the chiller tank water and certainly none in the chiller tank. Thermal convection should be all the pumping you need if solid ice cannot form. [Slush is probably OK, but IDK.]

Wright

----------


## TyroneGenade

> Tyrone, I don't think it would make a difference. As I've said, I can get the chiller to become very cold in a short time by switching off the filter but it won't help because the fish tank will warm it up as soon as the filter starts running. The point I've been stressing is that the chiller tank and the fish tank are not 2 entities, as I've initially thought. They are one.


KL, your freezer is the heat sink. For it to work there needs to be an efficient exchange of heat between it (the freezer) and your tank. By having the extension of your tank (the hose coil) isolated in a glass tank (the chiller tank) not only does a temperature gradient form between the hose and the chiller tank but also between the chiller tank and freezer. Both gradients are filled with air which is a damn good insulator when not in circulation. By taking the hose out of the chiller tank and putting it in direct contact with the freezer you are removing that one gradient which will almost certainly buy you a degree or two and this is why:

The rate of temperature exchange is proportional to the difference in temperature multiplied by itself four times as well as the heat capacity of the substance. A large temperature difference exists between the hose (your tank) and the chiller tank so heat exchange is relatively fast; but only a small difference exisits between the chiller tank and the frezer and to make matters worse there is all they still air which isn't conducting heat so the heat exchange between the chiller tank and freezer is slow. This means that the chiller tank cannot keep pace with your tank as a consequence the thermodynamic equilibrium reached between the hose and the chiller tank is not the equilibrium that would be reached if the chiller tank were disposed of.




> Slush is probably OK, but IDK.


My dear Wright, slush is much better.:-) The temperature of an ice slurry is lower than ice alone. I think several degrees lower. Mix in some alcohol and potassium salts and you can make that ice slurry very very cold. Just ask your good friend Mr. Farenheit.

Ciao

----------


## whuntley

> [quote ]Slush is probably OK, but IDK.


My dear Wright, slush is much better.:-) The temperature of an ice slurry is lower than ice alone. I think several degrees lower. Mix in some alcohol and potassium salts and you can make that ice slurry very very cold. Just ask your good friend Mr. Farenheit. [/quote] 

I suspect you meant Fahrenheit?

We are not talking temperature, here, but how to move heat from fish tank to exterior of the freezer (the room). The *drop* in temperature is a direct measure of how much thermal resistance is present at each stage. If a large temperature difference exists between the wall of the freezer and the chiller tank, then slush may be much worse than liquid at reducing that temperature drop, because convection currents can't aid the transfer of BTUs. That's what I did not know. 

Frost, ice and (maybe) slush are your enemies, here. The function of the antifreeze is to keep thermal transfer high by keeping the fluid liquid. The absolute temperature is not lowered by making slush (except in water where ice has an anomalous coefficient of expansion). Once you add much antifreeze, the actual temperature of the slush can be any old thing, but you want to avoid any condition that allows a bigger temperature drop in the heat path. In this case, convection currents move warmer fluid to freezer walls to reduce the temp. difference. Slush may slow that process and allow a higher temperature drop, hence reduced efficiency.

In a somewhat ideal case, tyou are trying to raise the inner wall temperature of the freezer to something like 16C. If you have a 2C drop to the chiller tank, and another 2C drop to the fish tank, you will have the desired 20C in the fish tank. [Note that this would not allow any ice to form if dynamically stable.]

As I understand it, there is frost on the freezer wall so it is at about 0C and the bulk of the heat resistance is between the wall and the chiller tank. Reducing that loss (temperature difference) deserves a lot of thought.

BTW, there is no practical way to get the coils in direct contact with the freezer walls as shape and volume dictate that 99% of the coils would be in air, and the same heat block would be present and maybe worse.

Therefore:

a) You need a heat-conductive fluid coupling the freezer walls to the tubing walls. The present drop of essentially 20C is unacceptable and very inefficient. It makes the system more a room heater, and not a tank chiller.

b) You need to avoid formation of ice, frost, or slush by adding some antifreeze if they ever tend to form. This will tend to be true when you get the system so efficient that the freezer control cycles it on and off. You need to allow for the deeper drop (maybe below 0 in spots) during the on cycle to keep the 16C average.

Wright

----------


## TyroneGenade

I worry that with the coolant fluid the tank's temp may drop much more than 1 or 2°...

The ice on the sides of the freezer suggest to me that the chiller tank is the problem. If there isn't ice on the side of the chiller tank then the chiller tank is not cooling enough to be effective and this has nothing to do with the tank's temp. Did ice form on the chiller tank walls when the water flow was off?

tt4n

----------


## whuntley

> I worry that with the coolant fluid the tank's temp may drop much more than 1 or 2°...


That's what the temperature-control thermostat on the freezer is designed to handle.  :Smile: 




> The ice on the sides of the freezer suggest to me that the chiller tank is the problem. If there isn't ice on the side of the chiller tank then the chiller tank is not cooling enough to be effective and this has nothing to do with the tank's temp. Did ice form on the chiller tank walls when the water flow was off?


Ice on the freezer wall (0C or below) and none on the chiller tank (at 22C) is just proof that the air is a good insulator (assuming glass temp. drop is minimal) and that one needs to get it out of the system. The chiller tank is doing an excellent job of keeping the fish tank at nearly the same temperature (2C difference). Removing the air insulation is needed to move _both_ lower. One _hopes_ that does too much, so the freezer control can be set so it doesn't run all the time and burn out early.

Wright

----------


## timebomb

> KL,
> The fans will not help to bring down the temperature at this state.


You know what, Freddy? You're right on the dot with that one. The fans not only did not bring the temperature down but for some strange reason, the temp went up by 1 degree the next morning. So I switched the fans off and turned the settings of the freezer to midway. Not much point setting it to maximum when that doesn't help much. 

This morning however, the thermometer went below 24 C for the first time. It's probably due to the fact it rained last night but hey, who cares? I got 23.2 C. Hurray!!!!!!!



There was even some condensation on the sides of my fish tank. I checked the chiller tank and the temp there was 21.5 C.






> You should target nothing but all that is in the fridge.


Okay, friend, I'm taking your advice. But don't swear at me when you find out what I just did. I decided to do something about the water in the chiller tank. I added a powerhead. Okay, I know, all of you have been saying this won't help to cool the tank but warm it up instead. But hey, I'm a skeptic, remember? I don't believe anything until I see real evidence  :Laughing: . Here's a picture of my chiller tank with the powerhead installed.



Wright and Tyrone,

I appreciate your suggestions very much but I have to be honest and say I don't really understand what you wrote. I flunked Physics when I was in school, remember? Sorry about that, old chaps but you have to forgive me as I'm pretty dumb with many things. Anyway, the picture above shows some ice on the sides of the freezer walls and they stick to the glass. There's a big patch of it right behind the power head. The corners of the chiller tank are free from ice though and I wonder why this is so. 

Loh K L

----------


## PohSan

> The corners of the chiller tank are free from ice though and I wonder why this is so.


Maybe the cooling coil is inside the center of the four freezer walls. Since the ice is touching the tank, there is no more insulation between the freezer and the tank. I believe that the DIY chiller will be now working more efficiently.

Regards,
Ong Poh San

----------


## TyroneGenade

Ever the prophet of doom that I am, but... with all that ice forming you should perhaps be worried about that chiller tank cracking in two or three or four... I still say get rid of the chiller tank.

----------


## timebomb

> I still say get rid of the chiller tank.


I can't, Tyrone. The chiller's compartment is not meant for holding water. The guys selling them all say it will leak. As for the glass cracking, I was kind of worried about that but someone said it won't happen because it's equivalent to leaving a mug of beer in the freezer, he said.

Loh K L

----------


## TyroneGenade

No the tank cracking from ice inside but cracking from ice pressure forming from the outside. Ice forming around the hose is not problem because the hose can deform but the ice build up against the glass can perhaps cause problems. I am not a structural engineer though so my opinion isn't well weighted (to borrow a SG term).

----------


## whuntley

I agree with Tyrone that ice against the outside of the glass chiller tank could eventually crack it. It is a potential problem, but not at this stage where it is just thick frost.

Looking at the picture with frost touching the glass, I'd be inclined to guess that the internal pump will be a big help, depending on its power and efficiency. Even a small airlift system, like for UGFs would be enough to stir the water with minimal heating. The frost touching the glass isn't much better than air for effective heat transfer, BTW.

Let me try to clarify what Tyrone and I have been discussing. [I do not agree with some of Tyrone's points, BTW.]

Think of heat flowing as like an electrical current flowing through a conductor. A resistance will drop some Voltage, just as a thermal resistance will cause a temperature drop.

When heat flows out of your aquarium and is sent to the outside world by the freezer's output (hot) coils, the energy must flow through different parts of the system. When heat energy flows from one place to another (without any outside input of energy) then the flow will be from the warm tank to a place with lower temperature. The temperature difference is a direct measure of the thermal resistance between the warm and cool place for that amount of heat transfer.

Right now, it is only 2C or less from fish tank to chiller water, so the heat transfer efficiency of the coils is quite good at the present low heat flow rate. Since the freezer walls are making ice from condensed atmospheric moisture, they have to be at 0C or colder. All of the heat that flowed from fish tank to chiller water is being removed by the freezer. The 22C drop from chiller to walls is a good clue that the air is strongly insulating the chiller water from the freezer's coils.

It may actually *be* rocket science, but to any electroniker/laser guy, rocket science is pretty trivial.  :Laughing:  

Freezers should not be designed to leak. A freezer where a power failure allowed the ice to melt or the ice cream to run into the mechanism wouldn't last long in the market. If the inner case is strong enough to hold ice cream, it should be able to hold a considerable weight of water. Of course they are not *designed* to hold water, but they should, anyway. [A really good skeptic would question that store advice. :wink:]

Even if there are slow leaks from seams, a bit of good old aquarium cement (silicon seal) will easily fix that.

Can you add a few inches of water to the freezer compartment without flooding the carpet? If you can, try it.

I would expect the fish tank temperature to drop, the chiller tank to drop considerably more (i.e., more than the current 2C difference) and the freezer control would have to be set up to kick it off to keep your fish tank above 20C.

The leak risk is limited by the chiller tank, so only the small amount of water surrounding its base would be at risk. A few towels could absorb that much, even if it failed catastrophically. No?

Look at where the frost is forming, and assume that is close to the freezer cold coils. The water would probably have to be about that high for my suggestion to work, so the risk could well be more than you want to take.

What are balconies for?  :Smile: 

Try it, You'll like it!

Wright

Who is safe in CA if your downstairs neighbor comes after you with a cricket bat.  ::smt021:

----------


## timebomb

> [A really good skeptic would question that store advice. :wink:]


Ouch  :Opps:  you got me there, Wright.

Okay, I'm going to do as you suggested. But I will not fill up the freezer compartment with water as there are gaps in the seams. It will surely leak. 

I checked this morning and found that the ice has retreated from the chiller tank. Where the ice was touching the glass before, there's now a small gap. The powerhead is doing a good job preventing the chiller tank from cracking under pressure and good thing about it all, there's hardly any difference in the temperature. Here's a pic:



I went out just now to look for giant plastic bags. They are not easy to find but I managed to buy some from a shop along Haig Road. Here's a pic:



I will be replacing the chiller tank with this plastic bag. I'll double-bag of course as there's a chance the plastic will be punctured. I don't know if there's enough time to work on this today. I promised to bring the family to a movie. We're going to watch "Predator vs Aliens". I love the Alien series of movies; my daughters and I are big fans.

Maybe tomorrow. I'll let you all know the results. If this works, I'm going to take a cricket bat to the guy who suggested I use a glass tank. I'm going to claim the $40 I spent on the tank from him  :Laughing: .

Loh K L

----------


## FC

KL,



> The fans not only did not bring the temperature down but for some strange reason, the temp went up by 1 degree the next morning.


Yes, thats expected.


> So I switched the fans off and turned the settings of the freezer to midway.


Yes, so long there is ice at the Wall and nothing is done to twart it, the fridge can practically be switched off and still getting the 24 degree celius at the aquarium.
Let me put it another way:
The cooling coil (behind the Wall) is running at easily below -10 degree celcius. By allowing ice to form at the Wall will, effectively, build an insulation slap that limit the temperature at a useable 0 degree celcius. It is worse than the insulation of the air gap (between the Wall and the Glass) because air can go far below -10 degree celcius.
- Thats why there is a heater (not many people are aware) in our no-froze fridge used (at a set program) to melt any ice formed on the coil.


> I decided to do something about the water in the chiller tank. I added a powerhead.


The 2 degree celcius difference between your Chill Tank and the Aquarium indicated the 50 m hose is doing a fantastic job in the heat exchanging. Trying to bridge the gap further is meaningless and ineffective.
You see, the difference between the cooling coil (assume -10) and the Chill Tank (22) is 32 degree celius! Now, it is obvious this is the place where any slight effort would yield great benefit.
- Imagine that the difference were to be improved by just 10 degree celius, thats the Chill Tank will be 12 degree celcius (all the time), the Aquarium will easily be lowered by at least 4 degree celcius to 20.


> There's a big patch of it right behind the power head. The corners of the chiller tank are free from ice though and I wonder why this is so.


I concur with Poh Sans explaination.

----------


## timebomb

> You see, the difference between the cooling coil (assume -10) and the Chill Tank (22) is 32 degree celius! Now, it is obvious this is the place where any slight effort would yield great benefit.


Okay, fellas,

I did as you all suggested. 

Yesterday, before leaving for the cinema, my wife and I siphoned out the water and took out the chiller tank from the freezer. We then replaced it with the big plastic bag I bought. I decided to use only one as double-bagging may create air pockets which you all said are no good for chilling the water.
Here's a pic:



It was a bit difficult to tie up the bag nicely so I cable-tied both ends of the opening, rolled up what was in between and use clothes pegs to hold it in position. Before that, I put in the powerhead. Here's a pic:



After everything was rigged up nicely, I switched off the filter and started the freezer running. I then went for the movie with my family. Great movie but it can't compare to the Alien series. 

Okay, back to topic. When I came home from the cinema, the temperature in the chiller bag was about 13 C. I started the filter running. This morning, I woke up hoping to see something really cold. Shucks. The temperature of my fish tank was 24.5 and that of the chiller bag was 22.7 C.

Well, folks, so it looks like I was right all along. We're back to square one.
I should have been more of a skeptic  :Laughing:  

Loh K L

----------


## timebomb

Hi, folks,

Using a plastic bag instead of a glass tank to hold the water in the freezer didn't make any difference but I noticed something this afternoon. It could be I just wasn't paying attention before but today, I saw condensation on the filter hose, the one that goes from the freezer into the fish tank. Here's a pic"



Does condensation indicate anything, other than the water coming out from the freezer is cold?

Loh K L

----------


## TyroneGenade

Condensation suggests you have high humidity and a cold hose. 

I would be patient with the chiller bag... You have really upset the apple cart and it will take a while to stablize. It took 2 days wasn't it for the chiller tank to take the tank down from 28 to 24°C so it may take that long to get it down further. Maybe you should get rid of the powerhead and replace it with an airstone as someone suggested. You might win back 0.5°C.  :Laughing:  

By all rights you should have much better heat exchange between the tank water and freezer. It should be cooler. Much cooler. Perhaps one must just be patient.

Let us know how things progress.

On the bright side you now have another fishtank.  :Very Happy:

----------


## timebomb

> I would be patient with the chiller bag... You have really upset the apple cart and it will take a while to stablize.


That could be a factor, Tyrone. I'll wait another few days and if the situation does not improve, I will put back the chiller tank. I feel it's safer with the tank as chances of it leaking are lower.




> On the bright side you now have another fishtank.


That's a good one  :Laughing:  I had a good chuckle over it.

Loh K L

----------


## whuntley

KL,

Before this last change, you had set the thermostat higher on the freezer. Did you remember to turn it back down to max cold for this experiment?

If you did, then I think you just moved the temperature drop out to the walls, but have proven that your freezer only has the capacity to cool your tank a few degrees. Insulating tubing and cannister will get another few 10ths but possibly isn't worth the trouble.

The only thing that can do more is externally cooling the freezer with finned aluminum heat sinks or a fan or two.

Wright

----------


## FC

I strongly think that the present setup is gonna bring the aquarium temperature to at least 23 degree celcius, 22 is very very likely. Give it 1~2 days more when the bag's water goes below 20 degree celcius.

I guess it would reach an equilibrium of 18 degree in bag and 22 degree in aquarium with full thermostat setting. If it does not, it goes back to my first skeptic:
fc wrote:



> KL, 
> How much power is this fridge rated? I suspect your tank's size would required at least 100 watts model.


The pump you place in there will only be needed when the bag's water achieve below 18 degree celcius.

Remarks:
Sealing the bag is a good thing to do as it prevent moisture escape from it that was the water source for the ice formation at the Wall.

----------


## timebomb

Hi, guys,

I came home from work today to see 24.1 C. That's pretty good, considering how hot it is today. Room temperature is 31.5 and the temp in my chiller bag is 22.4. 

I switched off the powerhead in the chiller bag. Let's see if the temp drops further. 

Wright, when I replaced the chiller tank with a plastic bag, I turned the thermostat back to midway. It's been set at that level since.

I was discussing the DIY chiller with some colleagues and they all agreed that if I add salt to the water in the chiller bag, it will bring the temp down further. They can't explain why though but they all say ice creams sellers use salt to prevent ice from melting. I thought it was dry ice. What do you all think?

Loh K L

----------


## TyroneGenade

Salt will alter the chemical structure of water (i.e. how the little H2O molecules interact). This reduces their energy (because now that are lugging salt around) so the average temperature (which we measure as temperature) is lower. Alcohol does the same thing but it may leach into your fishtank via the plastic hose... although probably not.

The salt you want to add is potassium chloride. The temperature will however requilibriate to whatever temperature that is... which may just be 21 or 22°C again.

Give it a try if it isn't too expensive.

Ciao

----------


## whuntley

Salt is used in ice-cream makers to get a lower temperature, but the salt does not remove BTUs and create the lower temperature. It lowers the freezing point of the water, and that gets the liquid temperature down to good ice-cream making levels. The liquid is essential for heat transfer from the milk solution to the ice. The colder the liquid, the quicker the ice-cream forms.

Pure water freezes at 0C, and salt water freezes at 0F, or 32 defrees F lower. Solid ice can be at _any_ temperature below the freezing point of the particular solution. Good freezers run at -10F or below or 42 degrees below the freezing point of plain water.

AFAIK, the only effect of adding salt is to alter the freezing point. One has to add or subtract BTUs (Calories, kilocalories?) to actually alter the temperature. The ice can do that to ice cream if it is below the current melting point of the salt solution. Salting your chiller bag won't do a blessed thing, because no freezing or melting is involved.

Salt is used to de-ice roads, not because it warms the road, but because it dissolves in surface moisture and reduces the freezing/melting temperature of the ice, turning it liquid but at still the same temperature. They usually add black oiled gravel to collect some solar help, which does raise the temperature.

Wright

PS. There's no excuse for not lowering the thermostat setting to see where that takes you, KL. If the freezer is power limited and never turns off, it won't do a thing. OTOH, it might be all you need to do.

----------


## TyroneGenade

Actually, potassium chloride does lower the temperature of water. It is one of the novel properties of this salt. Your fish tank will probably raise the temperature unless you increase the heat sink capacity of the chiller bag...

So back to square one...

tt4n

----------


## whuntley

> Actually, potassium chloride does lower the temperature of water. It is one of the novel properties of this salt. 
> tt4n


I'm puzzled. Where does the energy to lower the water temperature go? The salt has only a negligible effect on the density (specific gravity) or thermal storage capacity. The ionization of potassium chloride is not an enormously endothermic reaction, so that isn't what lowers the temperature.

Tyrone. You aren't trying another scotch-and-water-diet theory on us, are you? :COOL!: 


Wright

----------


## TyroneGenade

Where do you find those smilies??? Let me guess... "view more emoticons."

This question of the KCl is a big mystery. I don't think anyone knows. Maybe because K is heavier than Na it can reduce the energy of the water... who knows... I do know now that I have time to digest you 2nd last post that I was talking out of my arse... your point about the salt disrupting the structure of water making it more difficult to freeze is more sensible so please don't  ::smt075:  

tt4n

----------


## whuntley

Suggestion for a mini-experiment:

Take some "No-Salt" o/e source of KCl, and drop a measured amount in a container with melting ice in water. What happens to the temperature? It drops quickly as the salt is dissolved and stirred, of course.

Now take a container of cool tap water (no ice) and repeat the test.


Wright \ :Very Happy: /

----------


## Robert

Hi,
Im new to this forum and at first I want to say hello to everybody! BTW, Im a German, so please forgive me some of my misspellings .
Can anybody explain to me why it is so important to get the tank temperature below 24°C? I live in a region where most of the year I have to use heaters to heat my tanks. I heat them up to 24-25°C. Should I throw them away and be happy if the tank temperature reaches the 20-22°C of the room temperature? Is 22°C not a little bit too cold for tropical fishes and plants? I think 24-25°C are perfect and there is no positive effect if the water is cooler than this temperature. Only if your want to breed some dwarf shrimps like Crystal Reds its really useful to have cooler water (which is no problem for me but for you). But I guess you dont want to breed any fishes or shrimps in your 380liters display tank, so why do you want to cool it to less than 24°C? 
Loh K L, if you have some problems with the leaking fridge, then try to find the leaks and use some epoxid resin (I hope that this is the right translation for Epoxid Hartz). There should be no problem while using it and it is much cheaper if you compare it to the special silicone for aquarium usage. A friend of mine used this resin to get his balcony water proof and it works fine. In my regions we have winters with temperatures up to 20°C but nothing happened to the epoxid resin on his balcony. Paint the walls of the fridge several times to be sure that you cover all leaks. It should work pretty good and if there is still a bigger leak, you can also use silicone for it. I dont know if it effect the tank water but I guess it wont hand over anything to the environment. Perhaps some of the experts here can say something about this artificial resin.

BTW, perhaps you can reach the 23°C-mark if you modify the fridge itself. Everybody seems to think only about the heat which comes from the tank but nobody thinks about the heat of the surrounding air. The whole fridge should have a good isolation but you changed the cover and it looks really thin. If you isolate the cover of the fridge in a better way, less warmth from the surrounding air can disturb the cooling-process of the tank water. It should be no problem to isolate the inner part of the cover with some styrofoam. 
To isolate the back and the bottom of the tank should also help a bit and nobody cares about these sites. If you have a rectangular tank and the width is only half as long as the length of the tank, then these 2 sites are 40% of the whole surface of the tank. You lose cold at all sites of the tank and if you can isolate 40% of the surface, you should see a big difference because heat can now only affect 60% of the surface and not 100%. This helps your fridge to cool the water and you should get cooler water in your tank (even if there is no need for much cooler water but you can also safe some energy and money if it works). 

Best regards

Robert

----------


## whuntley

Welcome to the forum, Robert.

Many killifish like sub-tropical temperatures. Aphyos from the highlands of Cameroon, Gabon, and Congo (or whatever it is called this week) live in small swift brooks that are not particularly warm.

Keeping them healthy and, particularly, breeding can mean maintaining them at 20-23C. _Diapterons_ and _A. jorgenscheeli_ are classic examples of cooler water killies.

Many plants, like the Madagascar Lace Leaf also do much better in cooler water. The SG guys are avid plant growers, too.

The two-part cement you refer to is, in English, epoxy resin.

The compact freezer uses the outer skin as the way heat is radiated or conducted to the room, so insulating it isn't a very good thing to do. It is already very hot to the touch. All refrigerators, freezers and air conditioners that use fluid pumping are heat pumps, with cold coils inside and hot coils outside. It might help a little bit if the heat could be drawn away from the hot case with fans or finned heat-sink material.

Your spelling is fine, and probably better than mine, if you use the neat spell checker that was just installed.  :Very Happy:  

Wright

----------


## Piscesgirl

> perfect and there is no positive effect if the water is cooler than this temperature. Only if your want to breed some dwarf shrimps like Crystal Reds its really useful to have cooler water (which is no problem for me but for you).


Are you saying that Crystal Red Bee shrimp need cooler than 25 C to breed? Mine breed fine at 78 F. (26 C?), and it sometimes get to 80 F.

----------


## FC

> I switched off the powerhead in the chiller bag. Let's see if the temp drops further.


Good move.



> Wright, when I replaced the chiller tank with a plastic bag, I turned the thermostat back to midway. It's been set at that level since.


The change to bag idea should work better. Now, you should set to maximum to see how far the fridge (for its' size) can bring down the Aquarium's temperature.



> I was discussing the DIY chiller with some colleagues and they all agreed that if I add salt to the water in the chiller bag, it will bring the temp down further.


Addition of salt is useless for your case. *Why?*
For such application, salt's sole function is to lower the freezing point of water and increase the heat (cold) storing capacity (if THAT water EVER freeze). For certain, your fridge does not have the capacity/power to froze the water in the bag.

If the water do freeze, then the addition of salt would facilitate the "salted" water to lower beyond zero degree celcius. This is then important and effective because it broke the zero degree barrier, thereby increasing its' capacity to cool, for your case, the hosed water.

----------


## timebomb

> Hi,Im new to this forum and at first I want to say hello to everybody! BTW, Im a German, so please forgive me some of my misspellings


Hello to you too, Robert. Welcome to the forum.

The weather here in Singapore is hot the whole year round. Mostly, the temperature of our tanks are about 30 to 33°C if there's no cooling equipment. With fans, we can get the temp down to about 26 to 28°C. That's low enough for most plants but to grow mosses and ferns really well, it's best to have temps of between 24 to 26°C. It's more for the plants than the fish.




> why do you want to cool it to less than 24°C?


I want to see 22°C in my tank for the same reason Sir Edmund Hillary wanted to climb Mount Everest  :Laughing:  Because I believe it can be achieved. 
The day the thermometer reads 22°C, I will turn the thermostat to set the freezer at a higher temperature. Even at 24°C like what the thermometer registered today, there's already condensation on the sides of the fish tank. Condensation would mean I can't see what's inside my tank but it feels good to know the tank is so cold. Here's a pic:






> if you have some problems with the leaking fridge, then try to find the leaks and use some epoxid resin


I appreciate the suggestion but there's no need to use epoxy resin as the plastic bag I'm using to hold the water works just as well as using the compartment itself. As for using silicon, a friend told me silicon works well only with glass. He used it on a tank made with acrylic and the tank gave way after a few days.




> The whole fridge should have a good isolation but you changed the cover and it looks really thin.


You meant insulation and not isolation, don't you, Robert? The cover I made for the freezer looks thin but there's a rubber seal on the insides along the perimeter. I believe it's quite effective keeping the warmth out and the cold in. 

I already have a piece of styrofoam on the bottom of the tank. Almost every hobbyist I know uses styrofoam to keep their tanks stable. I also have a piece of styrofoam glued to the back of the tank. It's wrapped with aluminium foil. It's there because the back of my tank faces the balcony where the sun shines in everyday. The foil bounces the heat away from the tank. I don't think it helps very much but hey, anything for another degree  :Laughing: 



It rained today for most of the afternooon and evening. Room temperature now is 29.5°C. It should be a lot colder tonight. The temp of my tank now is 24.0°C. I turned the thermostat to its coldest reading as Wright suggested. I pray [-o< I can see a temp of lower than 23°C tomorrow morning. 

Loh K L

----------


## TyroneGenade

Aren't there products that can retard condensation? I'm sure there is one that is used on bathrooms on tiles. I'm sure the principle is the same and it would work on glass. Any suggestions?

----------


## RonWill

> Originally Posted by Robert
> 
> 
> 
> 
> 
> why do you want to cool it to less than 24°C?
> 
> 
> I want to see 22°C in my tank for the same reason Sir Edmund Hillary wanted to climb Mount Everest  Because I believe it can be achieved


Guys, if the condensation isn't heavy enough, Kwek Leong won't have a reason to start on his DIY wipers!  :Laughing:  

The day when his tank stays at 24ºC, I'd want to see how his plants are doing. Then again, for someone with green wet thumbs, I doubt it would make much difference  :Confused:  




> The cover I made for the freezer looks thin but there's a rubber seal on the insides along the perimeter. I believe it's quite effective keeping the warmth out and the cold in


 Still, I don't think it'll hurt to have a snug fitting piece of styrofoam between the bag and lid.

I suspect if you insulate both hoses connected to the freezer, with air-conditioning foam pieces, the temp should drop a tad more.

Willkommen Robert. The only reason I would want my tank that cold would be to maintain and breed cool water killies, never mind the plants! [but wait till the electricity bill comes in!]

BTW, where is 'north of Germany'... Bremen? or you're not residing within Germany?

----------


## Robert

Hi,
I know that the weather is always hot in Singapore. I have some friends in the Lion City and I visit a handful of your forums everyday (because the ambience is better in your forums than in ours and most of them are very informative for me). So I still knew why you built a chiller but I couldnt understand why you want to have such low temperatures.
I got the idea of the insulation of your tanks back wall when I looked on your pictures. I couldnt see any insulation, just some paper which is not very effective. The idea of the better insulation of the fridges cover came when I read that you changed it and when I saw the picture of the new one. The new cover seems not to contain any coil and so it gives no heat up to the surrounding. But heat can come through it into the inside of the fridge, which influences the cooling-process. Perhaps there will be no difference if you use a better insulation but I thought its worth a try. 


I kept some Aphyosemion striatum in the past and I had no problem with them at temperatures of 24-26°C. The only problem were their aggressions against my guppies. The female killed almost one of them and she used every chance to bite my guppies. The male was not that aggressive but he also bit my guppies every now and then. But Im a guppy ( and dwarf shrimp) breeder and I need my males and females healthy and in good conditions, so the striatum pair found a new home outside of my tanks (I gave them to someone else). 
A. striatum and A. australe (often you can only get the xantic form which is called Cap Lopez here) are the most common killies in our LFS here in Germany. But you still have to look for them, they are not as common as cardinal tetras or guppies. 

Which species do you keep in such a huge tank? I always thought its better to keep killies in smaller tanks but you try to cool a 380liter tank, which is pretty huge for a killie-tank. 

By the way, I live in a city in the north-east of Germany, in the state Mecklenburg-Westpommerania. Take a look at the map: http://people.freenet.de/r.gall/Germany.jpg to find it. Its one of the most beautiful regions of Germany. We have about 2000 lakes (several hundreds of them are less than 50 kilometres away from me, its a paradise for fans of all kinds of water sports), lots of island in the Baltic Sea e.g. Rügen , our biggest German island and which is much bigger (975 square kilometres) than Singapore  ::smt003:  , beautiful fine white beaches and lots of pure nature with sea eagles and many other wildlife. Only the unemployment rate of 15 % (in the west of the state) till more than 30% (in the east) is a big problem for us. Now you should know a little bit more about me. 
BTW Wright, I learned English at the grammar school and I wrote my A-level exam in English, too, because it was one of my two main subjects (the other one was biology). 

I mentioned the colder water temperature for CR shrimps because many German breeders of this shrimp (including myself) experienced that you have much more egg-carrying females of this species if you keep them at 20-25°C. At 25°C and above most of them stop breeding and you get much less offspring. It is possible to keep them at 28-30°C and you will get some offspring but it is not as much as you could get at lower temperatures. I can watch this phenomena every summer when the room temperature reaches the 28°C mark (its almost the maximum which I can get in the room where the CR shrimp tank is). Fortunately our summer lasts only three months. 

Best regards

Robert

----------


## timebomb

> I always thought its better to keep killies in smaller tanks


Hi, Robert,

I'm quite sure that's a myth. Small tanks are favoured over big ones because Killifish enthusiasts always run out of space. I'm sure fish in general do better with more space. I have only a few Killies in my 380 litre tank. Just a couple of Nothos, a pair of Apistos and some Boraras spp. 




> The day when his tank stays at 24ºC, I'd want to see how his plants are doing.


Ronnie, the temperature hit 23.5ºC this morning but it didn't dip below 23ºC as I had hoped for. Anyway, I'm not sure about this but I believe the plants have been doing better since I fixed up the chiller. Here are some pictures of my plants:


The Downois seem to be producing more plantlets.


My Weeping Moss was all brown before I had the chiller


Not much difference seen in the Java Moss; they are one of the easiest moss to grow.


The Christmas Moss 


The lower temperatures definitely help with the Willow Moss


My coconut with Java Moss growing on it. I'm hoping the pair of Apistos will lay eggs inside.


Can't remember which Moss is this but it's probably the Nano Moss which Gomer sent.


The most beautiful moss of all - Taiwan Moss

Loh K L

----------


## TyroneGenade

You see by ditching the chiller tank you have gained a degree.  ::smt038:  Didn't I say you would?

If you want those Apistos to spawn bury the coconut shell a bit so the entrance isn't so wide. They like privacy. What species do you have? _borrelli_? They like it cool.  :Cool:  

tt4n

P.S. that Taiwan and weeping moss is really nice as is the Downois. Do they remain short like in the picture or get really busy and big? Back in SAfr we never saw such pretty plants.  :u:

----------


## Piscesgirl

The plants look great! I love all the Downoi!

----------


## timebomb

> You see by ditching the chiller tank you have gained a degree.  Didn't I say you would?


Yes, you did and I'm glad I followed your advice. Many thanks to everyone who gave suggestions and tips on how to improve the chiller. I'll be wrapping the filter hoses with insulation foam later. 




> If you want those Apistos to spawn bury the coconut shell a bit so the entrance isn't so wide. They like privacy. What species do you have? _borrelli_? They like it cool.


They are _borrelli_, I think but I'm not too sure. They're are my first Apistos. I'll see if I can get a picture later. They're quite big so I don't know if they will find the entrance too small if I bury the shell deeper.




> hat Taiwan and weeping moss is really nice as is the Downois. Do they remain short like in the picture or get really busy and big?


The Downois don't grow very tall. Nid, in Thailand who grows them far better than I do uses them as a foreground plant. You can see a picture of her tank here

Loh K L

----------


## Robert

HI Loh K L,
thanks for the information and the nice pictures. I never saw such a huge collection of different moss species in a single tank before. I really like it. In Germany we know only java moss and Riccia fluitans and even these plants are very rare in the LFS, so it's hard for me to create a nice looking moss tank. Java moss is not the best choice and riccia makes a lot of trouble sometimes. I also like the Downois but I would like to know its scientific name because I never saw this plant before. I guess it's a Aponogeton species but I'm not sure. 

best regards

Robert

----------


## timebomb

Deborah and Robert,

Nid, my friend in Thailand gave me my first Downoi. Nid's a very special girl. She can't speak English but her boyfriend, NongOil does. Nid's article about the Downoi (written in Thai) appeared in Nonn's AQUA magazine and is reproduced in English here in this forum.

Loh K L

----------


## whuntley

Robert's guess that the Downois is not a moss but an Aponogeton, is a good one, I suspect.

That could explain the quick meltdown in shipping, as that's not typical of the few mosses I know. It *looks* like an Apo, particularly in the straight down shot.

I certainly hope the shipping problems can be solved, for it would be a huge improvement (have an impact? :wink :Smile:  on the aquatic gardening scene here.

Wright

PS. On Sat. I'm driving to Lancaster, 200 miles south toward LA to pick up an entire fishroom full of tanks from a hobbyist who is getting out of fish. They will fill the pickup truck as there are:

10 - 5 gallon tanks
40 - 10 gallon tanks
12 - 20 gallon high acrylic tanks.
2 - 20 gallon long tanks
2 - 40 gallon acylic tanks 
16 - 1.5G "Critter Keeper" plastic tanks

You can imagine my problem when I mention that I live in a rented mobile home. Where do I put them? Hope Bill gets a good trade on some of those lovely mosses. I'm going to really need them!

----------


## A.Rashid

> The Christmas Moss


If I may add.. from the pix shown the apisto you have KL, is not a borelli but looks to like a viejita, I could be wrong as the pix shown is showing the top part of the apisto.

Too cold a temperature wont induce spawning but if they are comfortable enough they will give you some frys, with apistos never expect the unexpected. Hope they spawn for you. Good luck.

----------


## stormhawk

If I recall correctly the downoi should be called Dao Noi in their native language. Its a Potamogeton species but I forgot the actual name that Nonn or one of the Thai hobbyists onced mentioned in a previous thread regarding this plant. KL, I believe the name is in one of the magazines that Nonn gave you.

Your apisto, if it was that one-eyed one you mentioned, should be Apistogramma viejita if I recalled Azmi saying that was what he sold to you back then.

----------


## Piscesgirl

Downoi is Pogostemon Helferi per my understanding. I actually have a nice little bunch myself  :Smile:  hehe. I want mine to stay low and be a foreground plant. 

Here is a linked picture of the tank. Please forgive me if it doesn't work -- I know RonWill gave me a nice place for my pictures, but I want to see if a link from photobucket will work (Imagestation apparently was not killies.com friendly). 





KL -- I did read that article about Downoi here and that made me 'obsessed' with Downoi, finally getting some in March of this year, and another couple in April of this year. That was my birthday present to myself (March).  :Smile:

----------


## stormhawk

Sorry my mistake. Just re-read the article and came across the scientific name (_Pogostemon helferi_).  :Very Happy:  

Yes its a nice little plant but it goes for quite a sum locally as well.  :Confused:

----------


## tayhonglee

Hi guys,
Im Henry Tay. I hail from the beuatiful land of St George's Rd  :Very Happy:  I actually own a reef tank, and I have to admit I don't know the first thing about killies. 
But I saw your discussion about DIYing a chiller and I just had to comment a little.
I think a bar fridge would have more success as compared to the freezer that Mr Loh is using, even though a bar fridge has less btu.
The pictures of the freezer/chiller that were posted had lots of ice in them. I don't know why but ice in the freezer makes it a lot less cooler than it should or could be. 
I learn that from experience as Im a second hand dealer, and I come across lots of lousy old fridges with no built in heater (no auto defroster).As frost builts up, the freezer starts to get warmer. For example, frozen ice cream starts to melt.
So I realised no frost is good.
Also, bar fridges have this metal plate in their freezer compartment that Mr Loh called the thermal plate. I suppose that the plate has little tubes built in that allows the compressed coolant to expand. 
So this plate is very very cold. 
If you can submerge this plate in the small water tank, I think the water would get cold very fast. The air in the rest of the bar fridge might be not even be cool, but then it wouldn't be your concern. I don't know what a powerhead can do though. 
After reading your posts, Im also inspired to DIY a chiller for my tank. I will record and take pictures of the process and results and post it here as well. 
Great site!
Henry

----------


## timebomb

> Hi guys,
> Im Henry Tay. I hail from the beuatiful land of St George's Rd  I actually own a reef tank, and I have to admit I don't know the first thing about killies.


Welcome to the forum, Henry. I'm really glad you joined in the discussion.

I only had ice when I was using a chiller tank. Now that I'm using a plastic bag to hold the water, there's no ice in the freezer anymore. I'm not sure if the thermal plate in a mini bar fridge can do more than a freezer but my guess is it can't. Let's look at it this way. Suppose I fill up my freezer with water and not run the filter, wouldn't the water become ice eventually? It would be difficult to do the same with a mini bar fridge but let's say we fill up the whole fridge with water, would it turn into ice too? Impossible, right? Only the ice-making compartment will turn into ice; the rest of water in the fridge will remain as water. 

So how can a freezer be less efficient than a mini bar fridge?

By the way, Henry, I'm just walking distance from where you live. I'm at Towner Road. You're welcomed to pop over to see the DIY chiller. Just give me a tinkle before you come. My number is 63921969.

Loh K L

----------


## FC

Henry,

Welcome here.




> As frost builts up, the freezer starts to get warmer.


We shared the same thoughts, I had mentioned similar in earlier post. Such fridge (not like non-froze type) need routine de-ice for the fridge to work effectively. However, for KL's latest modification, this problem had been solved. The only issue left is the fridge power which is a tack too low.




> If you can submerge this plate in the small water tank, I think the water would get cold very fast.


This would be the ultimate solution. I thought of this too. However, this need modification on the gas tubing to bring down this thermal plate evaporator. It has to be done by workshop and then re-fill with gas.

----------


## tayhonglee

Hi again,

Thanks for the warm welcome guys.Made me feel right at home :P 

Im going to sacrifice one of my mini fridge and see how my DIY chiller works out. 

Good thing I was a mechanic during my army daze, so Im a little familiar with hydraulics. I plan to lower the thermal plate with copper pipings and elbows so that it could fit into a small container of water. 

No problems with refilling the fridge with coolant. I have a regular guy who service aircon and fridges in my shop.

I will let you guys know how things turn out. Only thing Im worried about is the tank water coming into contact with the copper tubes. I read that corals are quite sensitive to copper.

Take care of your fishies!
Henry

ps. did you ever visit Reborn? Its a marine lfs at Lavender. Real close to Towner and St Georges  :Very Happy:

----------


## timebomb

> Im going to sacrifice one of my mini fridge and see how my DIY chiller works out.


That will be great, Henry. We need a guinea pig  :Laughing:  to see if a mini bar fridge works just as well or better than a freezer. If you need help, just holler. I can come over and photograph the process if you don't already have a digital camera. 

Good luck and keep us posted. 

As for Reborn, I was there a couple of months ago but they specialise in marine fish. Killifish and aquatic plant hobbyists don't have much to look at in that shop. The marine fish are nice though but somehow or other, I have never taken a fancy to them. 

Loh K L

----------


## timebomb

Hi, fellas,

I bought the insulation foam today and will be wrapping the DIY chiller/freezer hoses with them later. 



I don't believe the insulation foam will help to lower the temperature by very much but hey, anything for another degree  :Laughing: . I got something else, however, that may help a lot. Look what I bought:



It's a coil of copper tubing, 50 feet in length. Compared to the 50 metre (164 feet) PVC hose I'm using now, this is very short. But the conductivity should be a lot better. I've been warned that my shrimps may die from copper poisoning but hey, I'm a skeptic, remember? But seriously, we won't know for sure until we try. I'll be monitoring the copper levels. I wanted to buy a copper test kit on my way home just now but the shop I stopped at wanted $22 for the kit. That's a bit high for a test kit considering I paid only $25 for the copper tubing. I'll see if I can find a cheaper copper test kit later. 

In the meantime, can I have your opinions, please.

By the way, I actually wanted alumiunium tubing but I went to several alumiunium shops and they all say there's no such tubing. The ones they showed me are either very hard (long straight pipes) or very soft (like alumiunium foil). 

Loh K L

----------


## whuntley

Hi KL,

I suspect the amount of copper you get will depend a lot on pH. The lower the pH the more copper, as I recall. Don't miss any water changes and keep pH above 7 and it might never show much. [OTOH I could be all wet and it could be lethal.  :Smile: ]

We used to kill velvet o/e by just dropping one copper US penny in a tank. It doesn't take much.

I wonder how hard it would be to paint the inside of the copper pipe with a thin coat of epoxy paint?

There really is aluminum tubing, about as stiff as your copper tubing. I have seen it many times, but haven't tried to buy it lately. Won't work with solder fittings, of course, but works fine with compression/flare fittings. It is a soft alloy (SO grade, as I recall). Check out the web sites of the big aluminum makers, like Alcoa or Reynolds for local distributors?

Wright

----------


## timebomb

Oh yes, Wright. Someone told me too that acidic water will react with copper. The thing he wasn't sure about is how lethal the reaction will be. He suspects though that it may help to kill off the algae in my tank  :Laughing: .

I'll see if I can get my hands on some alumiunium tubing later but in the meantime, let's see how good the copper tubing is. The coil I bought had a diameter that was too large for my freezer so I had to uncoiled it and rolled it up into smaller circles. I straightened out the coil and rolled it up again using a pail. My wife and maid helped and we had quite a bit of fun uncoiling and coiling the copper tubing. Here are some pictures:





I took out the 50 metre long PVC hose from the chiller and replaced it with the copper tubing.



Actually, I found out this afternoon when shopping around that the 50 metre long hose isn't really PVC. It's, as Wright have said earlier, Vinyl. PVC, according to the guys at the hardware shops is very hard and it comes it long straight pipes. Anyway, I dumped the PVC hose into the dustbin. There were many kinks along the hose and it was hell trying to coil it up. 

I also wrapped all the filter hoses with the insulation foam. Here's a pic:



There's a great improvement in the water flow which means the time the water stays in the chiller is now shorter. Coupled with a shorter copper tubing, I don't know how this will affect the temperature. But if I don't get 22 degrees tomorrow, I don't know what else I can do to improve the system.

I dropped by Eco-Culture again just now to pick up a Copper test kit. I actually visited Reborn first as I thought a fish shop specialising in marine fish would definitely have a copper test kit. But whadayya know? They have plenty of test kits but not the copper one. Bleah  :Shocked:  

Anyway, Azmi was very nice and gave me a copper test kit for free. I checked and the copper levels are zero. I'll see if it sky-rockets tomorrow.

By the way, guys, the pair of _Betta albimarginatus_ in Eco-Culture that I was interested in has spawned, I should have bought the fish. Shucks.

Loh K L

----------


## TyroneGenade

I do not think that copper will be a problem in your well planted tank and anoxic substrate when the copper pipe has matured. You should have enough free shulphide ions (S-) to react with the copper anc cause it to precipitate out of solution. I doubt you will register any Copper reading on your test kit.

Copper toxicity depends on the levels of Calcium and Magnesium in the water. The harder the water the less toxic the copper. For Indian Carp the LC50 at 96 hrs was about 0.5 mg/L and 11 mg/L for Channa punctatus at a carbonate hardness of 100 mg/L.

Now the bad news... there is a lot of residual copper on that pipe with the result that you are pumping a LOAD of copper into the tank. This is a major problem with new buildings as well. New pipes release a lot of copper in soft water initially and then mature (get coverred with insoluable precipitates). 

If you can, do a 90% water change right now and disconect the copper pipe from your system and first let water run through that copper pipe continually for about a week. At this point I am very worried for your Apistogramma and barbs.

I could be wrong... and there is no need to panic but you have been warned.

----------


## FC

I agree fully with Tyrone.

Copper will age over time (months/years) with water flow, forming some form of oxide on its' wall that is tough and inert.

----------


## timebomb

I found a dead _Notho rachovii_in the tank today. But he's the only casuality. The shrimps are doing fine. I took half of Tyrone's advice and changed about 50% of the water. Before that, I tested the water with the copper test kits and the readings were zero.

By the way, I didn't get 22 degrees C. But the thermometer is showing 23 degrees more often. The difference between the temperatures in the freezer and the tank has also become narrower. For the first time this afternoon, the difference was only about a degree as opposed to 2 to 3 degrees when I was using the so-called PVC 50 metre hose.

Loh K L

----------


## timebomb

Hey, fellas,

I didn't get 22 C but 23 C is pretty good. So I've decided to put my DIY chiller/freezer on timer. I'm concerned that if the freezer's motor runs 24 hours non-stop, it will burnt itself out very soon. I set the timer such that the freezer goes off twice a day, for half an hour before midnight and for another 45 minutes before dawn. Midnight to dawn is when the weather's the coolest so I think it's the best time for the chiller to be off.

I've also started my undergravel heating cables working. I had them in my tank ever since it was set up 2 years ago but not seeing any benefits to my plants, I switched them off. My tank, before I had the freezer was constantly around 27 so the undergravel cables never worked. But now that my tank is so cold, I suppose there could be some benefits.

I met a Frenchman several years ago. He works for an aquatic plant import/exporter somewhere in Holland. He told me his company conducted experiments on undergravel heating cables. They set up 2 tanks, one with undergravel cables and one without. They planted the 2 tanks with the exact same number of plants. All the plants were weighed to make sure both tanks got the exact same weight of plants. All other parameters - lighting, CO2, fertilisation etc were the same. After several months, all the plants were pulled out and weighed again. They found there was hardly any difference. In other words, undergravel heating cables don't work.

But hey, I'm a skeptic  :Laughing:  And I try anything. 

Loh K L

----------


## TyroneGenade

I have always found _Nothos_ to be quite sensitive to copper... others have not but then again I was keeping my _Nothos_ in quite soft water.

If the _Notho_ died from copper poisoning (which can't be proved) you must have a copper reading. But as your shrimps are fine it must be very low but certainly not zero.

Good to hear the fish are all doing well inspite of my gloom-and-doom prophecies.

tt4n

----------


## timebomb

> If the _Notho_ died from copper poisoning (which can't be proved) you must have a copper reading. But as your shrimps are fine it must be very low but certainly not zero.


It's all circumstantial evidence but it's quite clear the Notho died because of the copper tubing. I'm pretty sure about this because the day before, it was very healthy. I don't know why the other Notho didn't die though. There used to be 2 in the tank. Now there's only one and he's still alive and kicking.

I forgot to mention this earlier but the water in the tank exhibited a slight tinge of brown when I came home from work this afternoon. After the 50% water change, the brown tinge disappeared. I intend to change the water frequently over the next few days until the copper has matured or becomes inert or something. Surely, copper can't do much harm. The piping in my house are all copper pipes and I've been drinking water straight from the taps for the last 20 years. I'm still around so copper can't be that bad, right?

Loh K L

----------


## whuntley

Copper can be very very bad.

Our Environmental Protection Agency has started mandating the addition of strong caustics (usually sodium hydroxide or lime) to domestic water to hold the pH above 7.5 or 8. That retards the copper etching and (particularly) the leeching of lead from the solder joints.

Copper and lead are heavy-metal toxins, and they are not reactive enough to form the solid (sapphire) coating that forms on aluminum as soon as it is exposed to air. The patina (green coating) on copper and the whitish lead oxide film are just not solid enough to be really protective if the pH of the water falls below 7. [I have killed whole tanks of fish before I learned that.]

Of course the EPA mandate does a number on our fish if we let ammonium get much above zero (as in shipping). I add about a double or triple dose of "Amquel" to all shipping water in an attempt to avoid sudden deaths at the other end. YMMV.

Wright

----------


## TyroneGenade

> the water in the tank exhibited a slight tinge of brown when I came home from work this afternoon


This is probably copper sulfide. Copper will precipitate with sulfides (remember hydrogen sulfide gas produced in anaerobic substrates) an din effect be neutralized. The odds are the water pumped through the copper piping has peformed a similar trick and the pipe is now lined with an insoluable copper sulfide coating. 

Copper Sulfide will only dissolve at a rediculously low pH (so low I think the calculation I just did has to be wrong, I invite people more mathematically sure of themselves to look here:http://www.chem.ubc.ca/courseware/pH...8/content.html).

For now you are safe... but keep checking that Copper reading and doing water changes just to be sure.

tt4n

----------


## scstormwolf

how do you drill the hole on top of the fridge? 

This unit is certainly very interesting. What about using those mini portable fridge which are quite popular now in the market?

----------


## whuntley

Those use Peltier cooling, which is more efficient if applied directly to the back glass of the tank, I suspect. Unfortunately, they are too weak for most tanks.

Basically, they contain a thin plate that is like a whole bank of thermocouples. When heated a thermocouple produces a current when there is a difference in temperature between the "cold junction" and the "hot" junction. When *driven* by a current, a temperature difference develops across the thickness of the plate.

If the cold side is bonded to the aquarium glass, and some finned aluminum heat sink material is on the hot side (slots vertical to encourage convection?), you can create a cold spot in the tank wall. Use some silicone to bond another set of fins inside the glass to improve efficiency at the cost of good looks.

Unfortunately, you may need a half-dozen of them to make a significant difference in a larger tank. Insulate the tank ends, bottom, and back, too.

They make gadgets to cool the CPU in your computer that work on exactly the same principle. Both portable picnic coolers and CPU coolers usually also incorporate a small fan to cool the hot-side fins.

The same unit can be chiller or heater by simply reversing the current direction. My guess is that a 200L tank would need something like 300W of well-designed Peltier cooling/heating. Most picnic coolers are probably about 50W or less -- hence my guess of about 6.

Wright

----------


## scstormwolf

anyone thought of making this unit and selling it? 

If so, i am interested. 

Maybe I provide you with the necessary equpiments and you fix for me or you get all the stuff and you fix it. 

So anyone??? Price must be reasonable of course.

----------


## RonWill

> anyone thought of making this unit and selling it? 
> If so, i am interested.


Dear What's your name "scstormwolf",
I, too, am interested in rigging up petier-cooling for smaller species tank and it would be nice to know who I'm sharing the project with.

You may have noticed that over here, we address each other in our real names. None of us here really bite, except Budak (I think :wink: ), so do let us know who and where you're coming from. Much appreciated.

----------


## scstormwolf

Alright, my name is Sam. Singapore.

----------


## RonWill

Sam,
Thanks and welcome to the forum. Our purpose for petier cooling may be different; perhaps planted tank for you but personally, it's a goal to be able to maintain cool water killies like _Diapteron_. [real pretty fishes. Look *here*]

Although electronically-challenged, I can still help with drilling holes, some soldering and other odd end stuffs. When we're able to get all the parts together, I can pull in a friend to rig it up.

----------


## stormhawk

Ron, its Peltier, not petier.  :Laughing:  I've seen an article regarding this method on a Japanese killie hobbyist's site. You need an online translator to roughly understand what's on the site. Very simple idea like what Wright has mentioned earlier. The cooling effect, according to the article only takes effect in smaller tanks, perhaps 1ft tanks would be a good size to test. I can't recall where I came across this article but if I do I'll email you the link. Very simple idea using the Peltier element, a heatsink, a normal PC fan and a short length of tubing.

----------


## scstormwolf

i am using it for marine tank. but i believe it will do just fine. Anyway, I am looking to fix up a DIY chiller. Looking out for a barfridge right now. Still wondering if a mini fridge will work for my 3ft tank. But I doubt so.

----------


## timebomb

Hi, fellas,

The copper tubing didn't work well. With it, the temperature of my tank hovered around 23 to 24 C most of the time but the fish and plants were not taking it well. The other _Notho rachovii_ died 2 days ago although I changed half the water in the tank everyday. Here's a pic of the poor bugger before he died:



Almost all the other fish didn't show any signs of ill-health except for a Croaking gourami that developed some fungus on its back. As for the plants, a Tonina-like plant I had started to melt and some of my mosses began to turn brown. My Willow Moss, in particular, seemed to suffer more than others. It was looking great before I changed the hose into a copper tubing. Here are before and after pictures of 2 of my mosses, the Willow and a species of Fissidens Moss.

*Willow Moss - Before the copper tubing:*


*Willow Moss - 3 days after the copper tubing*


*Fissidens Moss - Before the copper tubing*


*Fissidens Moss - 3 days after the copper tubing*


So I decided to take out the copper tubing and replaced it with something else. Gan C W was with me and we went shopping for a better hose. We went back to the same shop where I first bought the so-called PVC 50 metre hose and they insisted that the hose I bought earlier was really PVC. They said there are 2 types of PVC, one hard and the other soft. The hard ones are what we used for piping around the house and the soft ones are used to make hoses. 

Anyway, the previous hose I was using is too soft and it kinks easily. So I decided to buy something thicker. The shop owner recommended this - a braided hose.



It's 50 metres long and is thicker than the previous hose I was using. It definitely won't kink but the conductivity will probably be poorer. The owner said it's PVC too and the cost for a whole reel is $58. Ouch. I decided to give it a try.




The temperature in my tank yesterday was about 24 to 25 C. The temperature in the freezer was about 20 to 21 C. Seems like the gap has widened because of the poorer conductivity of the hose. 

It seems like I won't get to see 22 C in my tank after all. Then again, maybe I will in December when the monsoon season comes around.

Loh K L

----------


## zmzfam

KL,

I noticed from the last picture that you are still tightly binding the coil. Why don't you loosen up the coil a bit.

As for the copper tubing, perhaps you can ask around if anybody can cure the inside of the copper tubing. I'm sure your house is using copper pipings (as do mine) and topping up direct from the tap does no harm as (has been mentioned previously) the inside of the copper will form an inert coating.

That said, however, the water coming from the water-tanks is slightly neutral to alkaline whereas the water in your tank is slightly neutral to acidic, and it is always in contact with the copper.

Did you test for copper again? I'm sure the test kit can picked up some readings if your plants are in that state.

----------


## TyroneGenade

Cap one side of the copper tubing, fill with water and leave in the sun. Change and test the water every now and then. When the copper pipe water tests 0 for copper try it in the tank.

tt4n

----------


## whuntley

Do as Tyrone suggests with one small addition. 

Add enough vinegar or pool acid to the water to overcome any buffering and make it definitely acidic, say a pH of 5.5 to 6. If the water is above 7 it will not show much when you test for copper. 

Do the pH test before and after the sun soak, to be sure the pH hasn't "bounced back." [Harder water may resist staying acid and more vinegar will be needed until all the buffers are used up.]

Wright

----------


## Kenji80

What is the glue that you use to join the inlet and outlet to the freezer?

Can I know the brand and where to get it?

Thanks.

----------


## Kenji80

Can someone help on this?

What do you all use to join the inlet and outlet to the freezer?

Thanks

----------


## stormhawk

Kenji80 (what's your name?),

I don't think there was any glue involved. Silicone sealant (aquarium-grade) would do just fine in securing in the inlet and outlet points and preventing any leaks. Read through the entire thread for a better understanding of how to construct the chiller and the necessary items for making one.

----------


## Kenji80

Hi timebomb,

Can I check with you where did you buy the braided hose? 

What is the size of the hose?

Thanks.

Regards,

Yongda.

----------


## Kenji80

Anyone can help?

Thanks.
Regards,
Yongda

----------


## timebomb

Here's the address of the shop:

Chuan Hup Huat
Block 809 French Road
#01-184
Kitchener Complex
Singapore 200809

The size of the hose is exactly the same as the one from Eheim.

Loh K L

----------


## RonWill

> Anyone can help?


Mon Oct 11, 2004 6:18 am
Mon Oct 11, 2004 12:09 pm

Yongda, most of the members here participate as hobbyists and do not monitor the forum 24/7, responding "_on time, everytime_" like Fedex.

Kindly exercise some patience, allowing time for people to respond and refrain from one liners.




> What is the glue that you use to join the inlet and outlet to the freezer?


 None. If you study the photos in earlier postings, the hose are 'joined' using hose connectors. Neither is glue used to secure the connectors to the freezer lid. Silicon will suffice.




> Can I check with you where did you buy the braided hose? 
> What is the size of the hose?


 Braided hose is available in most hardware shops and even neighbour stores. Look around and you'll be amazed by what you can use for the aquarium.

Size of hose is not important, unless you're modifying a freezer. What's important, is a size that fits your pump/canister filter.

----------


## Kenji80

Hi timebomb,

so the hose size will be 12 internal / 16 external mm correct?

Thanks a lot.  :Smile:

----------


## Kenji80

Btw today I just gone to the same shop.

I was told that the hose is $1.30 per metre. They told me that they do not 

have any 50 metres hose but only 100 metres.

Hey timebomb, did you remove the insulation on the cover of the freezer?

Thanks.
Regards,
Yongda.

----------


## timebomb

Yongda, I'm quite sure I didn't make a mistake with the length of the hose. It's 50 metres. At 100 metres, I doubt there will be enough space for it in my freezer. Buying by the metre will usually cost more. It's best to get the whole reel if you're going to use a freezer too.

I showed a picture of the freezer's cover in this thread. You must have missed it so here it is again:



Loh K L

----------


## TyroneGenade

Hi Loh

I'm sure it is floating about in the thread somewhere but could you let us know at what temp your tank is running currently?

Thanks

----------


## timebomb

Tyrone, 

My temperature now is about 25 C most of the time. It should be colder but I decided to put the freezer on timer. For 6 hours everyday, the freezer is switched off. I did this because I'm concerned that the compressor will burn itself out in no time if I let it run 24 hours non-stop. With normal usage, freezers and refrigerators have thermostats that cut off the power when the desired temperature is reached. But in the case of my DIY chiller/freezer, that never happens as the temperature in the chiller never falls below 22 C. 

After all the experimenting, I've come to the conclusion that I was right from the beginning  :Laughing: . There's no way to lower the temperature of the chiller as the fish tank will keep warming it up no matter what I do. I also concluded that the conductivity of the hose does not affect the temperature very much. Whether it's a copper tubing, a PVC hose or a braided hose like what I'm using now, does not make much of a difference. A longer length will compensate for poorer conductivity. It also does not matter whether I use a glass tank or a plastic bag to hold the water in the freezer. We can't get the water in the chiller to become any colder because (I repeat), the fish tank will keep warming it up. There's also no necessity to use a powerhead to circulate the water in the freezer but you all already know that. What is most important is the cooling power of the freezer and that is limited by the wattage. The other important factor is the ambient temperature. On cold days, I get 23 to 24 C in my tank. On hot days, it goes up to 26 C. But that's still pretty good, considering my tank was mostly 28 C before I had the chiller. 

All in all, it was worth all the trouble. Your opinions are greatly appreciated. Although not every suggestion worked, there were many valuable lessons learnt.

Loh K L

----------


## FC

Hi KL,

I have a suggestion to the timer usage. Instead of switching the freezer off every 6 hrs, do it more often and shorter stop period. For that I mean, stop more frequently, say every 2 hrs, and stop for 15 minutes each time.

There are 2 advantages:
1) the freezer's walls (where the condensor coil is) get cool more often, thereby increasing the cooling efficiency, lower elect bill.
2) the compressor get to rest/cool down more often and thus more reliable. And it starts off again not in complete cold state.

----------


## Kenji80

Hi timebomb,

1) What did you use to drill the holes on the cover?

2) Did you remove the insulation from the cover? Because from the look 

of the pic, it seems like you have remove it.

3) The cover of the freezer is quite thick right? How did you manage to 

put the inlet and outlet sockets to it?

Btw there is a device called fox controller where you can use to control 

the temperature.

Thanks.

----------


## timebomb

Kenji,

I did not use the original cover. I improvised my own. I use a piece of acrylic and on the perimeter, it's lined with a piece of angle iron. I used Oyama paper to make it look like it's part of my freezer. Here are some pictures I took when my friends, Deric and Melvyn were rigging up the cover for me. Fortunately for you, I didn't delete these pictures from my camera.













I'm curious about the Fox controller you mentioned. How does it control the temperature? Does it work like a thermostat? 

Loh K L

----------


## Kenji80

Try visit this URL. There are information about the fox controller. 

http://www.sgreefclub.com/forum/inde...fox+controller

----------


## zmzfam

KL,

looking at your cover, would it be better if the inside was lined with styrofoam or some insulation material?

----------


## Kenji80

Hi Timebomb,

will using a plastic container with water reduce the efficiency of the chiller 

as compared to glass or plastic bag?

----------


## TyroneGenade

Plastic is a poor thermal conductor and would not give you as good heat transfer as glass or thinner plastic.

----------


## timebomb

> looking at your cover, would it be better if the inside was lined with styrofoam or some insulation material?


Zul, the inside of the cover, along the perimeter, is lined with a piece of rubber. Rubber may not be as good an insulator as styrofoam but it's easier to paste. In any case, the temperature of the freezer is not affected much by this. I carried out an experiment the other day. I switched off the filter and after about 12 hours, the temperature in the freezer dropped from about 22 degrees C to 5. I then switched on my filter and in less than an hour, the temperature in the freezer rose back to 22 C again. During this period when the temp went from 5 to 22, the temp in my fish tank remained the same. I expected a drop of 1 or 2 degrees but there was hardly any change.

I wrote the other day that ambient temperature is a big factor. It's been quite cold the last week and now, I come home everyday to see condensation on the sides of my tank. The condensation is so heavy I can't see the inside of the tank. That's one problem with the freezer; I can't set a desired temperature. Strangely however, the thermometer has never registered a temperature lower than 23.0 C. It hit 23 on many occasions but somehow or other, it has never gone below that figure. Maybe I should change the thermometer  :Laughing: . 




> will using a plastic container with water reduce the efficiency of the chiller as compared to glass or plastic bag?


As Tyrone has pointed out, plastic is a poor conducter of heat when compared to glass. That's true in theory but in our case, it won't make much of a difference. The efficiency of the chiller remains the same; it depends on how high is the wattage. The efficiency with which the freezer can cool the tank depends on how large is the tank compared to the freezer. The material and quality of the hose is an important factor but length can compensate for poor conductivity. A long plastic hose works just as well as a short metal one. I tried using a copper tube but I ran into all sorts of problems. The copper killed the bacteria in my filters and the water in the tank turned cloudy. I also found out later that all my shrimps disappeared. 

All in all, I'm quite pleased with the present setup. The temp in my tank has never gone below 23 C but it's quite low generally. Even on hot days, the temp rarely goes above 25. That's a lot better than when I was using fans. Surprisingly, my electric bills has gone down since I had the freezer. Not much but I had expected a rise so I'm quite happy with everything.

Loh K L

----------


## Kenji80

So you set your freezer to run for 6 hrs and then stop for how long?

Thanks.

----------


## Kenji80

Hi timebomb,

Can I know the exact address of where you bought the giant plastic bag 

and how much does one cost?

Thanks.

Regards,

Yongda

----------


## timebomb

> So you set your freezer to run for 6 hrs and then stop for how long?


It's the other way around. The freezer runs for 18 hours a day and is switched off between midnight to dawn. 




> Can I know the exact address of where you bought the giant plastic bag and how much does one cost?


I bought a few plastic bags from 2 different shops. They are both in the Joo Chiat area. Here are the addresses:

Poh Siang Trader
29 Onan Road
Tel: 63482387

SKP Pte Ltd
64 Onan Road 
Tel: 63466121

As for cost, the plastic bags are pretty cheap. It's not worth the trouble hunting around for cheaper ones.

Loh K L

----------


## timebomb

Thought I show you guys how heavy the condensation is sometimes:


A fly came visiting today and got itself stuck to the tank:


Here's how it looks with flash:


Loh K L

----------


## PeterGwee

Hahahahaaaa..  :Laughing:  Die of a freezing death. By the way, how are the plants and critters doing since the "greenwater" and sudden meltdown of plants?

Regards
Peter Gwee :wink:

----------


## timebomb

Everything's fine now, Peter. On hindsight, I shouldn't have used the copper tubing. It killed all my shrimps and the bacteria in the filters. The tank turned cloudy as a result. I think some residue of copper stayed in my tank for a long time; many of my mosses turned brown and some plants died. Fortunately, almost all the mosses have recovered and they are growing much better than before, what with the colder temperatures now.

Kho aka Shortman brought a diatom filter to my house the other day. We started using it at about 4.30 in the evening. Kho left shortly after and I considered letting the diatom filter run until the next day. Thank goodness I didn't. About an hour past midnight, after about 8 and a half hours, I switched off the diatom. When I tried to carry it to my balcony to wash it, I found that the motor was so hot it could have burnt my fingers. I don't know if it would have caught fire if I had let it run the whole night. It took about half an hour before the filter was cool enough for me to touch it.

Loh K L

----------


## Kenji80

Hi timebomb,

Can I know the wattage of your freezer?

Thanks.

----------


## timebomb

I'm sorry. I would like to know the wattage too but the specs on the freezer are all worn out.

Loh K L

----------


## s050399b

btw, how come the images are not displayed?

----------


## zmzfam

> btw, how come the images are not displayed?


Did you read the replies in the thread you created ? http://www.killies.com/forum/viewtopic.php?t=1410

Refer to these two threads : http://www.killies.com/forum/viewtopic.php?t=1287 , http://www.killies.com/forum/viewtopic.php?t=1291

We prefer that you signed off with your real name, unless you're hiding from something. Also, do not expect to be spoon fed all the time as you have already been told to read through the FAQ/Technical Help sub-forum.

I just hope that the threads above will help solve your problem, as no other information was given.

----------


## whuntley

To change directions back toward the original subject, thought to share this with you:

I recently visited my local thrift shop (used stuff is donated and the proceeds go to charity) and I passed up a bar refrigerator that would have made a great chiller. Price? US$8.00!

I lusted for it, but had to admit that I had no place to put it that made any sense. Instead I bought a full size (18 cu ft.) frost-free refrigerator/freezer (that works) for $12. That one will replace the smaller one I have been using that has a broken temp. control. I have lost more than $12 worth of food because of the unreliable regulation. :Crying: 

Maybe I can use the old one to keep blackworms and other live foods out in my fishroom-to-be. Once unloaded and defrosted (the new one is frost free) I may be able to repair the control.

Do you have thrift shops like this in SG? Here folks get a deduction of income for donations to reduce their taxes, and the stuff sold is often very cheap.

I love the thrifts because they have soup bowls and other small ceramics that make great spawning containers, and I (once in a while) get a great deal on an aquarium. I picked up a 3G bow front with internal filter and hood for a couple of bucks, the other day. A 20G (12"X24"X18" high) was US$10 including a fluorescent hood and air pump, a couple of months ago.

No need for a chiller here, now. My fire went out this PM, so my fishroom was down to 20C. I received a bunch of _Het. formosa_ and Endler's from B. G. Granier last week, but it was too cold for the Endler's on the way. The adults arived DOA and the two babies born en-route kicked the bucket, yesterday. 

Wright

----------


## aquafans

Hi Loh K L,

Talking about drilling the cover, in the first page, I see that James' chiller use refridgerator not freezer and make a hole at the top.

Since I already have unused refridgerator and want to make a DIY Chiller, can you tell me how to drill it? does it need a special tool?, I have talked with people and they all said that its difficult to drill the refridge since it has 3 layers. 

Thanks

----------


## timebomb

> Since I already have unused refridgerator and want to make a DIY Chiller, can you tell me how to drill it? does it need a special tool?, I have talked with people and they all said that its difficult to drill the refridge since it has 3 layers.


The special tool you need is a drill, of course. It's used for drilling holes  :Laughing: .

If you're drilling through the top, you will hit a piece of styrofoam sandwiched between the 2 sides of the fridge. The trick is not to drill right through. First, core a hole on the top. You should then be able to see the styrofoam. Use a small drill bit to drill through this piece of styrofoam until it makes a mark on the other side. This is so you know where to core from the other side. After having core 2 holes on each side of the cover, you then squeezed your hose through the styrofoam. This way, there's no leak and the fridge will still be perfectly insulated.

If, by any chance, you decide to make holes on the sides of the fridge instead, take note that there are coils. If you puncture a coil, the fridge will not work anymore.

Loh K L

----------


## timebomb

> Do you have thrift shops like this in SG? Here folks get a deduction of income for donations to reduce their taxes, and the stuff sold is often very cheap.


We don't have thrift shops, Wright. 

Over here, when people don't want stuff anymore, they sell it to the guy known as a "karang guni", the rags and bone man. He in turn exports the stuff to our neighbouring countries like Indonesia. 

I wonder if "thrift shops" would ever work in Singapore. The closest thing we have to a "thrift shop" would probably be "Cash Converters", a shop that sells second-hand products. 

Loh K L

----------


## whuntley

> Originally Posted by whuntley
> 
> Do you have thrift shops like this in SG? Here folks get a deduction of income for donations to reduce their taxes, and the stuff sold is often very cheap.
> 
> 
> We don't have thrift shops, Wright. 
> 
> Over here, when people don't want stuff anymore, they sell it to the guy known as a "karang guni", the rags and bone man. He in turn exports the stuff to our neighbouring countries like Indonesia. 
> 
> ...


This may well be a culture thing, too. I noticed the Japanese want nothing to do with a used item, and the folks in the US got great deals on replaced auto engines, as a result. Many such traits seem to be widespread across eastern asia. I wonder if this is one of them?

Our culture is a bit schitzo on this. We may prize antiques, but want a new car that costs twice what a year-old one sells for. 

I'm not proud. I stopped by the thrift shop on my way home from our Tues. hike, this AM. Recent rains made the road very muddy and I wanted high-top hiking boots. I found a nearly-new pair, in my size, for only US$3. New, the same boots would have been over $100, I suspect. 

Now, back to your regularly scheduled thread...

Wright

----------


## RonWill

Kwek Leong, there are thrift shops albeit not everywhere. I help out at the Church's thrift shop and am also a regular patron.

Crockery, clothing, household items, books and other bric bracs going for a song. I've seen 2ft tanks going for $5, terra cotta pots for 50cents, letter racks for $1, etc. and... urm... what was this thread about? :wink: 

Back to those holes... "aquafans" (what's your name?)

There are powered drill attachments that has either fixed or multi-sized cutters which will first bore the pilot hole, followed by the final diameter of choice.

I love holes... check here for my *'Hole Cutter' page*.

----------


## aquafans

Thanks Loh K L and Ronnie

KL, when you drill the inner side of refridge, did you laydown the refridge, is it ok to laydown it ?

Hole cutters, thats what I need, I guess its wood type drill, right?
I plan to do this project next week, so I have to buy everything before they close during Idul Fitri.

Jan.

----------


## whuntley

It is considered a generally bad idea to turn a refrigerator on its side. I'm not certain why, but have been told that liquid refrigerant can run into the wrong part of the loop and greatly reduce the efficiency. Makes sense to me.

Wright

----------


## RonWill

Jan, 
These hole-cutters will work for acrylic, plexiglass and wood. It may cut through thin metal but I can't be sure.

I try not to DIY stuffs involving metal as these are more difficult to cut and finish, without resorting to expensive machinery or lots of elbow grease.

Good luck with your project and do update us along the way with pics, ya?

----------


## aquafans

Hi all, I've done with the DIY chiller project.


Specs:
- Minibar refrigerator, consume 75 watt
- 15 mtr water hose
- water come from powerhead inside the aquarium
- small fan (modified from kids toy)
- Temperature in aquarium is 25.x, before is 27.x (400 ltr)
- Temperature in chiller is 24.5



I'm expecting to get 22C in chiller, I think the system does not work effective, The ice compartment is frozen while water in hose container is 24c, its only a few centimetres between them, the ice even thicker before I use small fan (I though the wind will unfrozen the evaporator, but it is not). Whats in my mind is take off the evaporator plat and put it in the hose container, will it help? Any other suggestion?
[/img]

----------


## aquafans

I saw again the james' chiller photo, the thermal plate that laid below the hose actually is evaporator, thats why we dont see ice compartment.

I will need an expert to do this  :Crying:

----------


## timebomb

> I will need an expert to do this


I'm not sure of this but only in certain brands of bar fridges, the thermal plate (evaporator) can be moved. In others, it's stuck to the fridge itself so there's no way you can take it out and position it under your hose. 

But if you're already getting 25 C for your 400 litre tank, I would say you have already done well. Believe me, any colder and you will have to deal with condensation all the time. I run my DIY chiller such that it is switched off 6 hours a day. If it run it 24 hours non-stop, the condensation is so heavy I can't see my plants.

Loh K L

----------


## TyroneGenade

Hi Loh

I've had this thought in my head for some time and I can't get rid of it by normal thought experiment testing so here goes:

1) Your freezer can only remove so much heat per s (lets say 2W/s)

2) Your tank is shedding, say 4 W/s, and this rate is proportional to the surface area of the emmitter (the hose).

So, you are putting 4W/s into the chiller bag and the freezer is taking 2 W/s away. 

3) But the rate of heat transfer is proportional to the difference in heat between the source and the sink. 

So the heat sink (FZ) , chiller bag (CB) , hose (H) and tank (FT) eventually reach an steady-state where where the chiler bag can't absorb more heat till the freezer takes it away:

environment -> FT <=> H <=> CB -> FZ

Assuming that there is a direct correlation between heat loss and surfact area reducing the lenght of the your hose by half will mean your tank will shed 2W/s which is the same pace as what your freezer takes the heat away. This will force a new steady-state with more heat being taken from the tank. It will mean that the tank will initially gain some heat but should over time revert to a lower temp than before provided that the ambient room doesn't put more heat into the tank than the freezer can remove.

I think you need to get te knife out and experiment. 

Start by removing 1/4 of the hose and see what happens. If it doesn't work then you can get a hose connector and put it back on.

Keep well

----------


## timebomb

> .Start by removing 1/4 of the hose and see what happens. If it doesn't work then you can get a hose connector and put it back on.


Tyrone, are you saying if I reduce the length of my hoses, the temperature in my fish tank will become lower? Well, that's not hard to do. In fact, I can do much better than that. Besides shortening the hoses, I can also remove my other Eheim cannister filter from the system. Currently, I'm using 2 Eheims, one is running while the other is not. The water passes through the 2nd Eheim before it returns to the tank. 

I'll go about it this weekend and report the results. Actually, I'm quite happy with 24 C but I wouldn't mind seeing 22 C for once. 

Loh K L

----------


## TyroneGenade

What I am saying, is that if you reduce the length of hose in the chiller bag the freezer will be able to remove more heat creating a better heat sink.

The problem is that the chiller bag have already removed all the heat it can by the time the water has passed through 50% of the hose... A lot of experimentation will be need to find the optimum length. I'm sure a physicist could work it out for us but we don't have.:-(

Your 2nd Eheim may be an aditional heat gain for the tank but I can't see it being significant. Plastic is a good insulator... It has very poor heat transfer properties and air isn't much better.

What was the length of hose used for your friend's bar fridge chiller? and the tank volume? By chance he may of hit on just the right hose length.

Kind regards

----------


## timebomb

> What I am saying, is that if you reduce the length of hose in the chiller bag the freezer will be able to remove more heat creating a better heat sink.


How can it be, Tyrone?  :Shocked:  Common sense dictates that the longer it takes for the water from the fish tank to pass through the chiller bag, the colder my tank will become. You sure there's nothing wrong with your formula?

I have to say I'm sceptical that your suggestion will work. I want a second opinion  :Laughing:  If someone else says your idea is worth a try, I'll reduce the length of the hose by a quarter. And then if it works, I'll reduce it by another quarter. 




> What was the length of hose used for your friend's bar fridge chiller? and the tank volume? By chance he may of hit on just the right hose length.


I don't think he's that lucky  :Laughing:  His hose, as far as I know is just as long as mine. He's using a whole roll bought from the same hardware shop. It's 50 metres.

Loh K L

----------


## whuntley

> Originally Posted by TyroneGenade
> 
> What I am saying, is that if you reduce the length of hose in the chiller bag the freezer will be able to remove more heat creating a better heat sink.
> 
> 
> How can it be, Tyrone?  Common sense dictates that the longer it takes for the water from the fish tank to pass through the chiller bag, the colder my tank will become. You sure there's nothing wrong with your formula?
> 
> I have to say I'm sceptical that your suggestion will work. I want a second opinion  If someone else says your idea is worth a try, I'll reduce the length of the hose by a quarter. And then if it works, I'll reduce it by another quarter. 
> 
> Loh K L


Here's that second opinion (engineer style).

Any system for delivering energy (in this case "coolth"  :Very Happy: ) does best when all impedances are matched from source to load. A too-long (or too-small-diameter) hose passes the water too slowly for best efficiency, and a short fat one doesn't give enough contact time.

For a given set of circumstances of pump pressure, hose conductivity, diameter, etc., there will always be some length that extracts the maximum number of BTUs from the tank and moves them to the refrigerator. Calculating this often is too tough, so just experiment.

OK?

Wright

----------


## FC

KL,
You get more than 2nd opion  :Laughing:  .

Try this:
1) cut the tubing in the fridge into 2 halfs
2) run them in parrallel:
"in" -------============-------"out"
- the "====" are the tubings in the fridge running in parrellel
- the "----" are the tubings outside the fridge

Cutting short the tubing will reduce water surface contact like what you are skeptical of. But in this configuration, you get:
1) maintain maximum water surface contact with the fridge's cold.
2) reduce the resistance of water flow by almost half.

----------


## aquafans

In long run, the temperature in chiller should be only a bit lower than fish tank, 2 degrees celsius different is make sense, considering there are heat from light, filter and fish. Length of hose is only about time how fast that balance will get.

To lower one degree celsius of one litre water, you need one kilocalories energy (if I'm right).
In this case, if you fillfull the chiller tank with water (including a very long hose), thats will increase total volume of water to be coolth, in other words need more energy to lower the temperature.

So try this, get smaller and shorter hose, fill with water the chiller just above the hose level, it may lower the temp.

Sorry for my poor english, I hope you get what I meant.

Jan

----------


## TyroneGenade

Here is the essense of my argument again taken from a different angle.

You want to heat your room. The cold outside is drawing 100 W of heat from the house and has now equilibriated so that both the house and outside is 4°C. What do yu do? Build an igloo? No, you turn on the heater. 

The heater is now putting out 100 W of heat. This will raise the internal temperature slowly. Because there is little temp difference initially between the outside and inside the cold is drawing now less than 100 W of heat. 

Heat moves at a factor of (the heat differnece) squared. As the indoor temp raises more heat will leave. Eventually you will be at a point where you are putting 100 W into the house and 100 W is being drawn out. If the temp is now at 10°C and you can't up the heater output you are in touble. What can you do? Reduce the surface area at which heat is lost: put up curtains (glass is an excellent thermal conductor) and pad the walls with styrofoam (a shoddy thermal conductor). Now you are putting 100 W in and loosing only 50 W so the temp will raise to a new equilibrium level where again the temp diff is big enough for the available surface area to loose 100 W. 

This is the inverse of your situtation. Your freezer can't remove the x W of heat yoru tank is putting in. You can't change the surface area of the freezer but you can change the surface area of the hose---that is the surface area where the tank is shedding heat.

If you reduce the amount of heat entering the freezer then it will lower the equilibrium temp. It will take some time for this equilibrium to establish so don't panic! You will probably see an increase in temp initially but it should decline as the temp difference between the freezer and hose increases to the point where it will draw off as much heat as before... in theory at least.

tt4n

----------


## timebomb

Okay, guys, you got me convinced. Not that I believe it will work, mind you but I'm convinced that it's worth a try. If you ask me, the length of the hose is an important factor but I would imagine I should lengthen instead of shortening it. 

I'll work on it this weekend. I'll chop off a quarter first and see how things go.

Loh K L

----------


## TyroneGenade

It is a great pitty you can't stick a thermometer down the hose and find out where the water temp equals the chiller tank/bag temp. From that point on the hose would be useless... It may be that the chiller bag does 90% of its cooling along the 1st quater of hose. In that case lobbing off 1/4 won't make any difference at all..

Good luck

----------


## timebomb

> In that case lobbing off 1/4 won't make any difference at all..


Well, that isn't necessarily the case. Even if it does nothing for the temperature, the flow rate will definitely improve with a shorter hose. Before I chop the hose though, I'm going to be more *scientific* about it. If your theory is correct, the difference between the temp in my fish tank and the DIY chiller will become closer. I'm going to monitor the temp difference closely by taking down the figures every hour or so. Only then, will we know for sure if a shorter hose helps.

Loh K L

----------


## PohSan

Hi Loh,

If you are to record the temperatures for every hour, you may want to plot a line chart or presents them in tabular format. It will be useful to determine the best time to power off/on the "chiller". And if you are going to experiment with different hose length, it might be useful also.

Regards.
Ong Poh San

----------


## TyroneGenade

Any change? Did shortening the hose have any effect?

I'm really curious...

----------


## timebomb

I was too busy to work on the chiller over the weekend, Tyrone. But seeing how curious you are, I decided to do it just now. I knew before I started that its going to be quite a hassle but it turned out to be much more work than I had expected. I have a CO2 system positioned between the 2 Eheim filters which I have to remove first before I can do anything else. Here's a pic:



I've been monitoring the temperatures in the fish tank and the freezer over several days. I won't bore you all with the figures so I'll just show you all a summary:

The lowest recorded temp for fish tank is 24.0 C. For freezer, it's 21.6 C. Highest is 24.9 for fish tank and 22.9 for freezer. The difference between the temps for the fish tank and freezer fluctuated between 1.2 degrees and 2.8 degrees. 

Average difference over 36 readings taken at one hour interval is *2.06* degrees C. That's the magic figure, right? If shortening the hose works, this figure should become lower. In other words, the difference in temp between the freezer and fish tank becomes narrower.

I took off 12 metres from the 50 metre hose. It sounds like a simple matter to shorten the hose but the way the whole thing is rigged up, I have to ensure there's no water in the hose before I can start the filter running. If, at anywhere along the hose or in one of the Eheims, there's water, the thing won't run. An Eheim is a wonderful piece of equipment but it can't push water through that long a hose if there's already water inside. Imagine trying to get rid of the water in a 38 metre long hose. I thought about using a balloon pump but I couldn't find it anywhere in the house. So I had no choice but to uncoil the hose, lift it up so that the water flows out from one end and coiled the whole thing back again. Here's what I chopped off:



I'll let it run for a day before monitoring the temperature again. I'll let you all know if there's an improvement.

Loh K L

----------


## TyroneGenade

Hi Loh

If I new it was that much trouble I would of told you leave it... way too much work for 2°C...

Actually I'm hoping to see 2 things:
1) lobbing off a small section of hose makes no difference. This would confirm the hypothesis that your hose is too long and is shedding all the heat it can over the first few meters and that your freezer doesn't have the capacity to remove the heat being put into it.

2) that the temp difference between the freezer and tank increases but that there is a downward shift for both (i.e. your freezer sits at 18°C and your tank at 22°C)...

The 2nd point is the BIG experiment. Can we but reducing the length of the hose reduce the heat being put into the chiller tank so allowing it to cool further and draw more heat out. It sounds odd but that is why physicists who study thermodynamics get Nobel prizes.

I just tried to go and do the math to demonstrate but found myself reliving my undergrad years... I'm satisfied with the thoeries and leave the math to someone else... As someone pointed out the heat exchange depends on the flow rate of the water. On one site, using Newton's Law of Cooling, the heat capacity of water varies from 500 to 10 000 depending on the pace at which it moves!

tt4n

----------


## timebomb

> Can we but reducing the length of the hose reduce the heat being put into the chiller tank so allowing it to cool further and draw more heat out. It sounds odd but that is why physicists who study thermodynamics get Nobel prizes.


I don't think I'll win any prizes but I'll give it a shot. What you wrote makes perfect sense. By making the freezer colder, the tank should get colder too. And one sure way to make the freezer colder is to shorten the hose. I'll let the system run a few days before making the change. I'll take out the 38 metre hose from the freezer and replace it with the 12 metre that I chopped off. Even if the temperature does not get lower, it would be a big help if the flow rate becomes faster.

It may interest you to know, Tyrone, that I came home from work today to see my thermometer in the fish tank reading 23.2 C. It isn't the lowest I've seen but the temp in the freezer was 20.7, one of the lowest I've seen so far. We can't be sure this is because of the shortened hose though as it's been a very cold day today. The ambient temp is 27.0 C, far lower than the usual 30 to 31 C. 

Loh K L

----------


## TyroneGenade

hmmm... very interesting... I will reserve further commentary till after the experiment. In the mean time I will play with the math and build a model... see what I can find without causing you too much labour.

I need to know several things:
the volume of your fishtank
the volume of your chiller tank/bag
the diameter of your hose (inside and ourside)
average day temp
average day humidity

Keep well

----------


## keehoe

Today is a very cold day in fact.

----------


## RonWill

> It may interest you to know, Tyrone, that I came home from work today to see my thermometer in the fish tank reading 23.2 C...
> 
> We can't be sure this is because of the shortened hose though as it's been a very cold day today. The ambient temp is 27.0 C, far lower than the usual 30 to 31 C


Kwek Leong, your thermo reading looks good but I suspect the weather plays a big part.

The past week has been hazy and drizzly, getting pretty darn cold at night. The temp in my sump registers between 24.5 to 25.2 ºC and a good cool breeze makes those Henri filters even more efficient.

I'll be interested in the results with a shorter hose as I may have to rig one up for my pending 4tier x 3ft rack in the study. These will house my breeders and more maybe my shot at cool water killies. I'd rather keep all my tanks outside but... guess who came aknocking on my door.  :Confused:

----------


## PeterGwee

> I'd rather keep all my tanks outside but... guess who came aknocking on my door.


Who eh? The people from the town council or even worst..the police?  :Cool:  

Regards
Peter Gwee :wink:

----------


## stormhawk

With the current cool weather chillers are really having a field day. My thermometers registered a cool 24.1 degC earlier this morning without using Henri filters  :Laughing: .

----------


## TyroneGenade

Loh...

Actually I need the dimensions of your tank and hose and an approximation of the volume of your chiller bag/tank. Then I should be able to figure everything out. I will share the math and model when I have sorted everything out.:-)

The results may be surprising...

----------


## timebomb

Tyrone,

Here are the figures you want:

Volume of fish tank - 380 litres
Volume of Chiller bag - about 60 litres
Diameter of hose (internal) - 12 mm
Diameter of hose (external) - 16 mm
Length of current hose - 38 metres
Average day temp - 30 degrees C 
Average day humidity - 84.4 %

Let me know when you come up with a good length for the hose and I'll get to work right away. By the way, wouldn't the flow rate be a factor? I don't know what it is though. All I can tell you is that it's powered by an Eheim 2215. 

Loh K L

----------


## RonWill

> Who eh? The people from the town council or even worst..the police?


Peter, I transgressed no civil laws here so there's no need to fear the police. OTOH, my unexpected 'guests' are rightfully doing their jobs.

I'll have to 'tidy up' my act albeit taking a little longer than expected, especially with all the hanky panky activities in the tanks!

That said, a chiller sure looks tempting. Let's see if Tyrone's 'mathematical modules' will hold water... in this case, chill the tank!  :Laughing:

----------


## timebomb

> Let's see if Tyrone's 'mathematical modules' will hold water... in this case, chill the tank!


Ronnie,

Tyrone may come up with a good mathematical model for the system but I think I may have accidentally hit on the perfect length for my hose when I chopped off 12 metres. The temperature of my fish tank, ever since the DIY chiller has never dropped below 23 degrees C. There were a few occasions when it hit 23.0 C and I lost count of the number of times I stood before the thermometer when it was at that reading, hoping it will go lower still, only to see it rise. 

Last night, just before I went to bed, I took a glance and saw this:



Hurray!!! Maybe it's because of the cold spell we're having but I kind of believe it's got to do with shortening the hose.

Loh K L

----------


## shortman

Kwek Leong,

That is my dream temperature for my planted tank perfect for my plant.
I wander how is the killies doing in that temperature. :-)

BTW, how much is the electircity bill monthly so far?

Cheers.

----------


## timebomb

Kho, the fish are doing fine. I think they will have no problems even if the temperature drops further. I'm not sure how much the freezer costs me in terms of electrical bills but ever since I had it, my monthly utility bill has remained about the same. I can't give you a breakdown as there are many electrical applicances around the house but generally, my utility bill is in the region of about more than $300. What with 3 computers, 3 air-cons, numerous filters and air pumps, lights and all, I'm one great consumer of utilities  :Laughing: . My water bill alone is about $60 a month. 

I'm looking at my bill now and it says in the month of July, I used 1104 kWh of electricty. For August, it was 1455. The DIY chiller started running in the middle of August. In September, I used 1236 kWh. For October and November, it's 1207 and 1353 respectively. 

Loh K L

----------


## Tom Wood

Dunno how this all turned out, but has anyone considered just putting a sump inside the refrigerator? Use a regular bulkhead/J-tube out of the main tank into the sump inside the refrigerator, and then use a submersible pump in the sump to pump water back to the main tank. A big aluminum pot could serve as the sump. This would solve the thermal barrier problem of coiled tubing.

TW

----------


## ruyle

Hey Tom, welcome to killies.com! What you suggest sounds interesting,
but I don't know if an aluminum container would leach metal back into
the tank, or if it would be harmful, if it did. I'm thinking, why take the
chance? Maybe Wright will see your post and have some substantive
comments...once again, welcome!  :Smile:

----------


## whuntley

The coiled tube has some thermal resistance, but huge surface area, as compared to an aluminum pot (low thermal resistance but far smaller area). I wouldn't like to have a bet on which is more efficient, but my guess goes to the tubing. Best would be thin-wall aluminum tubing, which is widely used in refrigeration applications.

Copper is reactive and poses a heavy-metal poisoning threat, particularly if the pH should drop a bit. The aluminum is far more reactive, but that causes it to instantly (almost) form an inert skin of aluminum oxide (aka sapphire) on exposure to air. Long exposure to low pH might be a minor problem, but the aluminum is much less toxic than copper, I think. I still cook in aluminum pots, but never in one that is copper inside.

I guess one could attach a bunch of finned aluminum heat sinks, inside and outside of the pot to increase the coupling area. Arrange fins to be vertical to take advantage of natural convection currents.

Wright

----------


## whuntley

One added point:

Avoid submerged pumps, as they rely on water cooling (i.e., they heat the water). Pumps with air-cooled motors might help efficiency, if venting is good.

I used to use a small waterfall pump to distribute water from my RO and tap sumps. I was amazed at how warm they got when I forgot to turn the pump off!

Wright

----------


## timebomb

Glad you decided to join us, Tom. Welcome.

I don't think using a sump inside the freezer would be of any help. I haven't got round to do it yet but I'm going to shorten the hose inside the freezer to just 12 metres. Presently, it's 38 metres long. As it is, the results are more than satisfactory but I want to prove the point that the length and conductivity of the hose won't make any difference to the efficiency of the system. We're having a cold spell now and the temperature of my tank is about 22.5 degrees C on most days. There's heavy condensation on the sides of the tank, so heavy I can't see what's inside the tank. 

Loh K L

----------


## PohSan

I strongly believe that the temperature of the tanks depends the efficiency of the freezer and the insulation to prevent heat gain as in 




> heat removed by the freezer (A) = heat gained by the tanks from the surrounding + heat gained by the hose between freezer and tank (B).


If A>B, the temperature will dropped and if A<B, the temperature will rasied. It is quite straight forward. Compare the temperature difference between the tank and the freezer and we will know roughly how efficient is the freezer. If the difference is 1 or 2 degree C or less, that is already the maximum heat the freezer can removed and length of hose play little here. I would suggest switching to a more powerful freezer (larger wattage). 

Regards,
Ong Poh San

----------


## Tom Wood

Understood, I was just making a late suggestion.

This won't work in non-airconditioned rooms, but I just added a radiator to my 90 gallon. The tank is fully enclosed except for the front glass, and the lighting makes a lot of heat. So a pump sends out water through an aluminum radiator which is cooled by a small fan. Depending on the ambient temp in the room, it can pull the temp of the water down several degrees (F) overnight. The radiator is actually a transmission oil cooler bought from a local auto parts store. 

FWIW

TW

----------


## TyroneGenade

1) do not use Aluminium. It will upset your plants as any dissolved Aluminium will compete with calcium in the plants (and fish) and stuff its physiology.

2) freezers are pretty well insulated as they are. I doubt you could do better. The point of heat exchange is the grill at the back through which the coolant is pumped. It takes heat up out of the freezer and exchanges with the air using some nifty physics.

3) there 3 types of heat exchange: raditation, conduction and convextion. witht he tank we are dealing with the last 2. Heat enters the tank by conduction (and convextion if the air around the tank is moving) and exits via convextion in that a moving body of water transfers the heat from the tank to the freezer.

The rate of heat transfer for conduction is dependant on the nature of the substance being heated and surface area exposed to heating. By insulating your tank you can prevent heat gain.

The rate of heat transfer for convextion is dependant on the nature of the substances exchanging heat, the surface area of the exchanger, and rate of coolant movement and turnover.

By shortening the hose you increases the rate of coolant turnover. You seemed to have gained a little on the swings but may well loose on the merry-go-round. A faster pump my help out with heat exchange but this isn't going to help if your freezer isn't pumping the heat out.
 
This is the major problem. You freezer is at capacity but has so far done a terrific job.

I've been investigating the physics behind your tank but I can't get past the fact that I don't know how much heat your freezer is removing. The physics involved with convextion also hurts my brain and I've pretty much given up...for now. My engineer will return from his holiday in a few days and then I pass the problem onto him but don't expect results.

For the mean time: hooray! your tank is cool.

----------


## Piscesgirl

22.6 degrees (72.6 F?) sounds pretty cool -- what ultimate temperature are you aiming for? 22 degrees C is what my house temp is right now...being we're in Winter. (I'd actually like it to be much warmer, but don't want to pay the heating costs for it to be warmer). Killies are happy at 22 degrees? I've always thought Killies were tropical warm-water fish until I stumbled upon your DIY chiller thread.

----------


## whuntley

Deborah,

Most killies are comfortable in the mid 70s F. It depends on where they originate. Some Chromaphyos live near the coast and won't breed below 78F but many other kinds come from highlands and will not reproduce at above about 72F.

On average, killifish are cooler-water fish than most of what is sold as "tropical fish" at the LFS.

Wright

----------


## Tom Wood

> 1) do not use Aluminium. It will upset your plants as any dissolved Aluminium will compete with calcium in the plants (and fish) and stuff its physiology.


Huh, I've not seen evidence of a problem. My aluminum radiator has been running for a month now. It's my understanding that aluminum creates a protective coating that renders it essentially inert, at least in freshwater with the sort of parameters we want for our tanks.

TW

----------


## TyroneGenade

Hi

Here is some data:
plants: 1 to 2 mg/l at pH 5
humans: 4 mg/L
These are levels at which aliminium will begin to exhibit toxic effects.

It was previously beleive that Al was linked to Alzheimer's disease. We now consider it only a minor risk for this disease but it has been shown that even in low amount it can impair nervous function as Al accumulates in brain and muscle tissue.

Its trick is to bind to a protein called calmodulin that is critical in cell signaling and response. This protein also exists in plants and by the sane nechanisms it can cause trouble for plants stunting there growth.

Now the first thing one should notice is that it is only toxic to plants at pH 5. At this pH the Al hydroxide scale begins to disolve and the Al comes into solution. 

But we maintain our tanks at 6.8 and 7!!! Yes but this is a general reading. If you stick the pH probe into the gravel I bet you will get a different reading. Likewise, if you had a micro probe and stuck it into a bacterial biofilm---for instance growing on the surface of an aliminium pot---you would again see a very low pH. This is because plants and bacteria generate reducing environment around them to better assimilate nutriens that would ordinarily not be soluable. A biofilm left to work on an aliminium cooking pot could end up releasing a lot of aliminium into solution. If you pH is acidic there will probably not be enough OH to complex witht he Al and precipitate allowing it to accumulate in plant and animal tissues.

It would take a long time for the aliminium to accumulate to the levels where it will exert toxic effects but it will get there.

The best options for a metal heat exchanger would be stainless steel IMHO.

Regards

----------


## whuntley

> The best options for a metal heat exchanger would be stainless steel IMHO.


The thermal conductivity of stainless steel is simply pitiful. I have never seen it used in any effective heat exchanger (but I haven't seen everything).

I suspect Tom will never see any problem, as water changes will keep any trace of Al well below dangerous levels. [There is a lot of hysteria about aluminum cookware on the net, but most of it is simply not true.]

The coating on Al, after air exposure, is oxide, not hydroxide. Sapphire is quite insoluble at any reasonable pH, AFAIK.

Wright

----------


## TyroneGenade

Gard darn it Wright you right! Its oxide not hydroxide... I feel like such a fool!!!

You are quite right about the cook ware. Unless you leave your pickled fish to soak in the pot for a long time the odds are slim you will suffer much Al toxicity. But it does accumulate in the tissues.

As for stainless steel... well yes. It sucks for cooking but it also doesn't corrode and let nasties off into the water. I should of clarified my opinion.

tt4n

----------


## Tom Wood

> The coating on Al, after air exposure, is oxide, not hydroxide. Sapphire is quite insoluble at any reasonable pH, AFAIK.


So, does this mean I should open the radiator up to the air now? Or will it become inert anyway? I do 20% weekly water changes, so this is probably not an issue, I'm just curious.

TW

----------


## Piscesgirl

Thank you Wright for that clarification -- Would they do ok in the upper 60s F.? If so, how would I know which ones?

----------


## whuntley

> Originally Posted by whuntley
> 
> The coating on Al, after air exposure, is oxide, not hydroxide. Sapphire is quite insoluble at any reasonable pH, AFAIK.
> 
> 
> So, does this mean I should open the radiator up to the air now? Or will it become inert anyway? I do 20% weekly water changes, so this is probably not an issue, I'm just curious.
> 
> TW


No, the tubing in the radiator was no doubt coated within minutes of being made. It doesn't deteriorate, so that initial oxidation should last a lifetime.

Deborah, 

Check the atlases for typical conditions. The coolest-water killies tend to be Gabon Highlands fishes, like _A. jorgenscheeli_ and _Diapterons_.

From the new world, many NA _Fundulus_ species and SA annuals from Uruguay and Argentina, like _Cynopoecilus_ and _Austrolebias_ qualify.

Dale Weber assured me that he broke through ice to collect _Cynop. melanotaenia_, I think in S. Brazil or Uruguay.

Wright

----------


## Piscesgirl

Alright, Thanks Wright!  :Smile:

----------


## whuntley

We do drift OT here, don't we?  :Very Happy: 

Getting back to chilled tanks, the killietalk list has had a good thread, recently, on cool-water fishes. Since SG has the opposite conditions, I suggest it is an interesting read.

I went back to ebay, this PM and was floored by the bargain Peltier (thermoelectric) coolers for sale. In anticipation of our hot summers, I am still thinking of a good, general-purpose system that should be way cheaper, and far, far more compact, than the freezer/bar refrigerator design.

[Am I nuts? It is -6C outside right now! When I got back from Reno, yesterday, I had no water. My pipes were frozen! Water from the toilet, boiled and then poured over them, fixed it, OK. I forgot and left two outside faucets open, so had to wade to turn them off.  :Opps:  My toes are still cold!]

Any way, the problem of condensation rears its ugly head in humid places like SG if you ever get a tank cool enough for Diapterons. Has anyone considered various schemes for keeping mirrors clear in the bathroom, etc., for keeping visibility acceptable on chilled tanks. Clear plastic film, like Saran, must work to keep the cold glass from becoming obscure. No? How to mount it?

How about wetting-agent sprays to cause the condensation to not bead up?

I'll be getting some processor chillers and TE plates, soon, and mating them to black anodized plates to go down inside the back of the tank. They will work great here, but I feel we must make the tanks aesthetically acceptable in SG if the solution is to be universal. Suggestions?

Wright

PS. I bought a nice bunch of 50W heaters and will cut my house-heating bills as soon as they are installed.

----------


## FC

Wright,

Do you think you a coat of "Rain-X" (a form of silicon) would help?

----------


## whuntley

I don't know, Freddy.

My ability to create a fogged tank is pretty limited, summer or winter, so the solutions may need to be found and tested in SG. No?

Be very cautious with sprays, as they may be lethal if any gets into the water.

One I would try, if I had condensation problems would be a frame/gasket made of 1/4" clear acrylic square rod, with Saran or other clear food wrap stretched smooth on it. If you can't install it totally dry, a small packet of dessicant between the glass and plastic might be needed.

Wright

----------


## keehoe

Aluminium is poisonous but Aluminium Oxide is not. Al is highly unstable that would ever ready to oxidise. You can only get the poison by scraching off the thick Al oxide. But again within fraction of second the surface turn into Al oxide again. Al is good electricity conductor Al Oxide is not. Ever try to use carbon to di oxidise Al Oxide? How much energy is required to make that possible? I think naturally, it won't happen.

----------


## whuntley

While studying thermoelectric alternatives, I came across this site:

http://cgi.ebay.com/ws/eBayISAPI.dll...349529953&rd=1

Since it is an asian product, it might be reasonable to order in your part of the world.

The big advantage of thermoelectric units is the ability to either warm or chill, and this one seems to have that feature. The circuit may be simple, but the design is more tricky than it appears to be.

Do note that the degrees are probably F and not C.

Wright

----------


## timebomb

I replaced the hose inside the freezer just before I left for KL 2 weeks ago. Now, it's just a 12 metre hose, much shorter than the 50 metre one I started with. As far as I can tell, the temperature of my fish tank remains about the same, at between 23 to 24 C. The temperature of the freezer though has gone much lower. Now it hovers at about 17 C most times. 

So I think I was right about the length of the hose having little effect on the efficiency of the system. I wonder how short I can go though. If I cut the hose to only say, one metre, would the results be the same?

A short hose would mean the water that flows from the fish tank stays inside the freezer for only a short spell. But it would stay in much colder water so the overall results remain the same. A short hose also improves the flow-rate.

Loh K L

----------


## TyroneGenade

You had 50m of hose to begin with correct ? You have tried 37 and 12m... now try 25 and see what happens... That your freezer is cool suggests that the system is performing slightly more efficiently. You should be able to find a hose length where both the freezer and tank are cooled at an optimum.

tt4n

----------


## timebomb

> You had 50m of hose to begin with correct ? You have tried 37 and 12m... now try 25 and see what happens...


Well, I don't know if I really want to try that, Tyrone. My guess is if I use a 25 metre hose, the temperature in the freezer will rise to between 19 to 20 C. My fish tank temperature should remain at about the same as it is now, between 23 to 24 C. 

I'm skeptical that there's an optimum length. I have already tried different lengths, 50, then 38 and now 12. The temperature of my fish tank was the lowest at about 22 to 23 C when the hose was at 38 metres long but I suspect it was because it coincided with the cold spell we were having in Singapore. Now, ambient temperature has gone back to about 30 C and with a 12 metre hose, I'm getting 23 to 24 C in my fish tank. 

One mistake I made when recording the temperatures of my tank and freezer when the hose was 50 metres long was that I didn't take note of room temperature. It's an important factor and I should have realised that earlier.

I'm glad I decided to take up your earlier suggestion to shorten the hose though. A shorter hose makes for a much improved flow rate. If I should change the length of the hose again, I'll probably try one metre. 

Loh K L

----------


## TyroneGenade

Hello,

I here it is warm again. What is the temp of your tank currently? Has it changed very much if at all?

tt

----------


## timebomb

Tyrone,

Yes, it's been real hot recently. Room temperature now is about 32 C. I don't know what it is like outdoors but it's scorching. 

I made some changes to the DIY chiller recently. A couple of weeks ago, for no apparent reason, a few of my Otos in the tank died. The water was also always misty. My wife kept complaining that there must be something wrong with the system. I checked with a friend and he said that the braided hose I'm using could be the cause. He said I should use an Eheim hose which, according to him, does not contain phenol. I googled for Phenol and here is what is said on one website:

_HIGHLIGHTS: Phenol is a manufactured substance found in a number of consumer products. Skin exposure to high levels of phenol has resulted in liver damage, diarrhea, dark urine, and hemolytic anemia. Phenol has been found in at least 481 of the 1,467 National Priorities List sites identified by the Environmental Protection Agency (EPA)._

So I decided to change the hose into an Eheim one. 

The hose is 10 metres long and I also changed the settings in my timer such that the freezer now runs for only 16 hours a day. During the first few days when the weather was cooler, the temp in my tank was about 24 to 25 C. Now, it hovers around 26 C. The water is no longer misty and no fish died. I suppose the braided hose I was using earlier may have contain phenol but I don't really know for sure. I'm quite sure I can lower the temperature further if I let the freezer run for longer hours but considering how hot it is outside, I'm quite content with 26 C.

Loh K L

----------


## skhastagir

dear all
how is the chiller working now? i am planning to build a similar chiller but i may use aluminium tubing .please advice.
thanks
sugato

----------


## timebomb

Dear Sugato,

The DIY chiller is still working fine. 

I suppose with an aluminium tubing, you should see better results. But the most important factors are the size of the tank you want to chill and the chilling capacity of the freezer itself. 

When I started, I wanted my tank to be as cold as possible. But on hindsight, I would say that isn't a good idea because when the tank becomes too cold, there's condensation. It's fun to see condensation on the sides of the tank once in a while but it's a big bother when it happens too often. 

So whatever you do, you should take into consideration your room temperature. Too great a difference between the temperature of your tank and your room will result in condensation.

Loh K L

----------


## skhastagir

dear Loh KL
thanks for your reply. yes you are right.i would like to avoid condensation.can you tell me what sort of temp diff causes condensation?
for example my room temp in summers is around 29 C, so till what temp can i go down without condensation?
in your opinion what is the ideal range of temp to maintain in planted tank?
thanks
sugato

----------


## skhastagir

dear Loh KL
also i know copper tubes are not good for the tank inhabitants. can you confirm that aluminium tubes coming in contact with tank water can cause any harm?
is there any definite source to confirm that?
thanks
sugato

----------


## timebomb

> is there any definite source to confirm that?


Sugato,

I don't think aluminium will cause any harm but Tyrone who's a chemistry teacher said this:



> 1) do not use Aluminium. It will upset your plants as any dissolved Aluminium will compete with calcium in the plants (and fish) and stuff its physiology.


I wouldn't want to argue with Tyrone over this as he probably knows a lot more about metals than me but I would think that even if aluminium dissolves in water, the amount would be so little it wouldn't do any harm.

If I were you, I would just go ahead with the aluminium tubing. You'll never know until you try.

Loh K L

----------


## timebomb

> can you tell me what sort of temp diff causes condensation?
> for example my room temp in summers is around 29 C, so till what temp can i go down without condensation?
> in your opinion what is the ideal range of temp to maintain in planted tank?


Sugato, 

If your room temperature is 29 C, I would say you should aim for 24 C in your tank. With mine, condensation does not occur when the tank is 25 C and above. My room temperature is about 30 C mostly, 33 C occasionally.

I'm not sure what's the ideal range but I know most plants will do okay at temperatures of 28 C. Some are okay even with temperatures as high as 33 C. Only mosses, ferns and certain species of Aponogetons require low temperatures to grow well.

By the way, where do you live, Sugato? Are you from Indonesia?

Loh K L

----------


## skhastagir

dear loh k l 
you have a pm.
thanks 
sugato

----------


## timebomb

Dear Sugato,

I checked but I couldn't find any private message from you. Are you sure you send it correctly? In any case, there is no need to inform me of a private message. If there's one, I will know. We want this forum to be a place where users treat each other with respect and consideration. To post a message that is of interest to only one person is disrespectful of others because you'll be wasting their time when they click on your post. Please do not do it again. Thank you.

Loh K L

----------


## skhastagir

dear loh K L
point well taken.i will keep that in mind.as regard to your question i am not from indonasia but from india.
will keep the forum updated about my chiller developments.right now busy in procuring the parts.
thanks
suagto

----------


## timebomb

Yes, please let us know how things work out for you with your DIY chiller, Sugato. Don't be too disappointed if the temperature in your tank does not show a sharp drop after the chiller is rigged up. It takes time for a DIY chiller to cool a tank. With mine, it took more than 24 hours before there's a significant change in the temperature. A tank takes time to be cooled but the good news is it also takes time for it to be warmed up again.

Loh K L

----------


## whuntley

Dead soft aluminum tubing may well be pure aluminum. If so, it should be quite safe. Aluminum quickly oxidizes, on exposure to air, to form an extremely inert coating of sapphire (aluminum oxide) on its surfaces.

I would worry if a bit of copper or other heavy metals were used as an alloy to "improve" the properties of the tubing. That just might permit some leakage of toxic products if the pH gets very low. It might be worth some Google searching to see what standard practices are in the industry, before risking any fish to long-term exposure to chiller tubing of aluminum.

Just being a worry-wart.

Wright

----------


## BeyondGomer

http://www.efunda.com/Materials/allo...m/aluminum.cfm

All you want to know about aluminum

Example for the composition thatyou are asking about. 6061 is extremely common..atleast for me when I machine parts.
Element Weight % 
Al 97.9 
Si 0.60 
Cu 0.28 
Mg 1.0 
Cr 0.20

----------


## eddy planer

Hi Loh,

Am new here....read about the DIY thread till almost 3.15am ( unitl my wife start pulling my ear to bed!)  :Shocked:  .

If you dun mind.....I would like to go ur place to take a nice look at your wow DIY chiller of ur. I thought using the used Polyscience chiller mainly used for research laboratorys to use for my newly 3ft startup plants tank to breed killies or drawf chillids like Rams or smaller types. 

I always a failure to grow mosses...due high temp. 29-30 'C.

If you dun mind......share wif me pls.

just ring me...+6593869654....I be there if you are free.hopefully during weekdays  :Wink:  .

Thank you for attention.

----------


## timebomb

> Am new here...


Hi, Eddy,

If you noticed, nowhere in this thread (which consists of 22 pages of posts), did anyone write in sms shortforms. Since you're new to the forum, we will forgive you. But please take some time to read this before making your next post.

We may seem like we snobbish but we have good reasons for insisting that all users make an effort to spell correctly. To be honest, if your post had been a private email, it would have gone straight into my trash bin and your request would be ignored. Please don't take offence. It's nothing personal. We just don't encourage "butchering" of the English language, that's all. 

You're welcomed to visit and see the DIY chiller up close but I won't entertain any requests that are filled with deliberate spelling errors. 

Loh K L

----------


## EvolutionZ

hi guys, i am seriously interested in making this DIY chiller. for my 2ft CRS tank. anyone did a diy chiller and can keep 2ft tank below 24C?
please give advice and comments on the DIY chiller..
and also where can i find cheap 2nd hand bar fridge? i hope i can find something like what KL you posted in page 1. james's bar fridge chiller.
thanks alot
regards, 
venson.

----------


## timebomb

Venson,

Before you get yourself the bar fridge, you may want to take note of this - 

About a year or so ago, one of the members in this forum asked me for help to rig up his own DIY chiller. He had already bought a brand new bar fridge and needed my help to drill the 2 holes on the top of the fridge. We brought the fridge to a friend who had all the necessary equipment and tools for the job My friend proceeded to drill the 2 holes but the moment he drilled the first one, we could hear a hissing sound. It was the sound of gas escaping from the fridge. 

For reasons we could not understand, the gas leaked when a hole is drilled on the top of the fridge. My friend bought the same brand of fridge as the one James was using, LG. We don't understand why James did not encounter the same problem when he drilled the 2 holes on the top of his fridge. It could be that although they were the same brand, the fridges were of different models. 

Anyway, the fridge no longer worked after the gas leaked out. My friend had to call off the project. As for my DIY chiller, it's still working fine. The temperature of my tank hovers around 26 degrees C on most days. On raining days, it can be as cold as 23 C. Occasionally, there's condensation on the glass. I have Crystal Red Shrimps in the tank and they have been breeding.

Loh K L

----------


## EvolutionZ

hi KL,

the bar fridge is in my house now. my uncle gave it to me. i already have the drlling equipments.. tomorrow will be doing the drilling.. after reading your post. im worried that my fridge's gas will leak.. maybe you can ask james why when he drill the hole. the fridge didn't leak?
anyway. my bar fridge was rated 95watt.

venson

----------


## EvolutionZ

hi KL,

i have got a good news. i went on to did the drilling with risk. and im glad that after 2 holes is drilled. i hear no hissing sound at all. went to silicon the fitting in. got to wait for a day for silicon to dry  :Laughing:

----------


## timebomb

Hi, Venson,

I'm glad that things work out well for you. It's a mystery to me why the gas leaked when we drilled my friend's bar fridge. I've already asked James about this when it happened but he did not know the answer either. 

My friend actually went back to the shop to enquire about the position of the coils in his bar fridge. But the sales people there had no idea where the gas coils were located. They never thought that anyone would want to drill holes into a brand new bar fridge.

Loh K L

----------


## EvolutionZ

hi KL,

i will be fitting a 35x28x15cm box in the fridge.. also along with 10m of PVC hose. bought from Nature Aquarium in thomson. its the replica of ehiem hose. size is 16 according to NA's boss. i am wondering if my ehem 2213 (440l/hr) canister filter will be able to push through the 10m long hose? 

anyway. im waiting for the silicon to try.. Saturday morning will start everything running and moniter the temp. thanks

venson.

----------


## timebomb

Venson,

I'm not sure if it's a good idea to use a PVC hose. It may be of the same size as an Eheim's but there's something about PVC that could be harmful to fish and shrimps. If we are simply using a PVC hose to change water, it won't do any harm because the water passes through the hose just once. But now you are going to rig the hose up such that the water from your tank passes through it continually. Over time, the hose will contaminate the water in your tank. You can prevent this by changing the water often but then again, I would advise that you keep a close watch on your shrimps.

Your Eheim 2213 should be strong enough to push the water through 10 metres of hose. If it does not work and no water is coming out of the outlet, it would mean there's a blockage somewhere. Even a little bit of water anywhere in the system would prevent the filter from working. I don't know if you understand what I mean but if you run into problems, call me at this number - 97951519.

Loh K L

----------


## EvolutionZ

hi KL,
im not sure if the one i bought is PVC.. didn't ask the boss too. but i use the hose for my filter. as in i use the same type of hose for my filter inlet and outlet.. used it for 3months and it didnt gave me any problem.. i still do 10 - 20% weekly water change. anyway to ID if my hose is PVC?
the hose is green also. exatly the same as eheim just that its a replica of it.
thanks for you help.
venson

----------


## timebomb

I think what you bought is "imitation Eheim". It's green and looks just like an Eheim hose but it isn't. It's a lot cheaper than the real Eheim though. I don't know about others but I'm quite happy to pay more for a genuine Eheim hose. For one thing, it never hardens like other ordinary hoses do after a while. 

I'm not sure but I think you can tell a genuine Eheim hose from its imitation by the numbers that appear at regular intervals along the hose. In your case, you should see 12/16 mm 4004940.

Loh K L

----------


## EvolutionZ

Hi KL,
so is my hose PVC? i bought it at $2 per meter... dun wan to waste $20 just to change to ehiem.. ehiem is $3 per Meter at C328.

----------


## timebomb

I don't know enough of plastics to tell you for sure but I think your hose isn't PVC. In any case, your hose should be okay as you have already used it before with your filter and you didn't encounter any problems. 

Loh K L

----------


## EvolutionZ

hi KL,

will start running everything tomorrow. still waiting for silicon to harden.
will post pictures of it too =)
thanks alot.

----------


## EvolutionZ

heres some explaination to go with some photos!

firstly, i'll post my bar fridge specs. you can use a Freezer. but i would recommand a bar fridge for any tank small den 3ft. a freezer would be a better chioce cause there will be much more space for the tubes to be in.


heres how the inside of the fridge looks like


basically.. the making of the DIY chiller will be. placing 1 tub of water in the bar fridge. with as much hose you can coil inside. for me. i used 10m of eheim replica hose. didnt get the eheim hose as its quite expensive to get 10m. so i got the fake version. 

Drilling is required. for hose connection from your aquarium to your filter. meanwhile. it will pass by the long hose in the cold tub of water. that will cool your tank down.
Drilling in process!


do watch out for coils on the fridge. i tested and run the bar fridge first so that i know where is the coil. when the fridge is running. the side and top of the fridge will get hot.. so drill 2 holes where the coils are not there.

2 holes drilled!


okay. now you should get ready the hose and the tub. like what i said, i used 10m of 16mm hose. filter im using is media fully packed eheim 2213(440l/hr). i noticed my filter flow rate reduced by 1/4 - 1/3.. that dosn't really matters to me.. so for a 10m hose. minimium are a 440l/hr or best get a 700l/hr and above filter for better results.

----------


## EvolutionZ

after drilling. its time to silicon the filtting to the holes.. so that it can hold the hose properly.
for me i DIY-ed the fitting myself. i found 1 hard tube in my storeroom. and also pushed 2 short hose inside so that it works like a stopper. den silicon.

a close up of the fitting
it looks the same from the other side

okay.. finally a day has pass and my silicon should have dried. i connected the hose and placed the tub in.. with 10m of hose in the tub

heres how the hose is connected.

after that. went on to connect my filter to it.. thats when i noticed my filter flow rate is reduced.. everything is now connected and runing.. but i still haven on my fridge yet. waiting for tomorrow morning so that i can observe my temperature closely.. just to play safe for my CRS tank..


Thats the end for now. i will post my how many C is my tank after fridge is running.
oh ya anyway. do note that before turning on the fridge. turn off your filter first den you start your fridge. cause your fridge takes shorter time to chill the water in the tub with the hose in.. rather then to chiller the tub of water in the fridge and the whole lot of water in your tank. after the water in the fridge is around mid 10C its time to on your filter again.... 
cheers!

----------


## timebomb

Nice work, Venson.

By the way, is there water in the tub? On your picture, the tub (holding the hose) appears to be empty. Is it really? 

Loh K L

----------


## EvolutionZ

hi KL,

no water in the tub yet.. cause tomorrow den i will start the fridge.. so gonna pour in water tomorrow  :Very Happy:

----------


## EvolutionZ

about the temp... my father this morning went on to start the chiller.. pour water in the tub.. and set thermostat at 2. and guess what... my temp now is 24C with my 2ft fan still on..:eek: 

now i turn off my fan.. set thermostat 1 and put lots of ice cubes iinside the water.. :Very Happy:  im quite happy with the results.. but i still need to observe for a period of time :Very Happy:

----------


## timebomb

Venson,

You sound like an intelligent young man so I'm puzzled why you choose to dumb yourself down by spelling "then" as "den". Why make yourself look stupid when you are obviously someone who's quite bright? Don't tell me they didn't teach you punctuation and spelling when you were in school? Why do you put dots between all your sentences? Is that really the way you think?

Okay, now that I got that off my chest, here are a few pointers for you:

Firstly, you do not need the fans anymore. It won't help to lower the temperature further now that you have rig up your tank to the DIY chiller.

Secondly, as your bar fridge cools the tank, the tank is also, at the same time, warming up the fridge. With a normal fridge, the thermostat kicks in every now and then when the desired temperature inside the fridge is reached. With your setup, the thermostat will never kick in because the temperature inside your bar fridge will always be quite high, around 22 C.
This would mean that the compressor will never stop running. I'm not sure but I think the compressors of fridges are not made to run 24 hours non-stop. 

I would suggest you put your bar fridge on a timer You can set it to stop running for half an hour after every 6 hours. Alternatively, you can set it to stop running between midnight and dawn when it's most cool.

Loh K L

----------


## carlfsk

Hi Loh,

I have posted this in another forum. But I thought we can discuss this here as well.

Do you think it will be a better idea to let the water flow into a reservoir(kept in the bar fridge), chill it within the reservoir, before flowing back to the tank? I know that for Arctica chiller, there is a reservoir within whereby the coil is inside. The tank water will circulate in this reservoir, chilled down by the coil, before returning into the tank. Can this principal works in this freezer / bar fridge DIY chiller?

This method will allow the tank water to mix freely with the water in the 'reservoir', thus doing away with the needs of the long coil of rubber tubing.

----------


## timebomb

Of course it would be a better idea, Carl. In fact, that's how a real chiller actually works. The problem is how can this be done with a bar fridge? Let us know if you have any good ideas.

Loh K L

----------


## EvolutionZ

guys, i got bad news. My temperature now is 27C even though my fridge thermostat is at 5. i noticed that theres no cool air inside the fridge at all. maybe a little.. think the frdige is too old or lousy...
Now the thermostat is at full power of 7. if my tank still maintain at 27C, i will call this project a failure.  :Crying:

----------


## carlfsk

Hi Loh,

how about using those air-tight type tupperware as the reservoir? Remember the advertisement about this air-tight tupperware by the name 'Lock Lock' or something.

Drill 2 holes at the cover as the in and out of water flow. Then use those PVC connector (those with thread) to screw / connect through the holes for the pipings / tubes.

I even thought of using this as a CO2 diffuser at the same time.

What do you think of the idea?

----------


## timebomb

> guys, i got bad news. My temperature now is 27C even though my fridge thermostat is at 5. i noticed that theres no cool air inside the fridge at all. maybe a little.. think the frdige is too old or lousy...
> Now the thermostat is at full power of 7. if my tank still maintain at 27C, i will call this project a failure.


It's still too early to come to a conclusion. It could be your fridge isn't in prime working condition but more likely, what's happening to your fridge now is what I've said earlier - As the fridge cools the tank, the tank warms the fridge. So in all probability, your fridge will feel rather warm when you put your hand inside. I believe, if you put a thermometer inside your bar fridge, that the reading there will be about 2 C degrees lower than the temperature of your tank. 

One thing you should keep in mind is your room ambient temperature. You had good results the day before yesterday probably because it was a cool day that day. 

Don't be too discouraged if things don't turn out the way you have expected. The system needs a bit of tweaking before it produces good results. I would say you should aim for a temp of 25 C. That should be low enough to keep the Crystal Reds happy. Any lower and you will have to deal with condensation which can be quite a bother after a while.

Loh K L

----------


## timebomb

> how about using those air-tight type tupperware as the reservoir?


Hmm, I don't think it will work very well. Using an air-tight container isn't very much different from simply using hoses. If it's going to be a tupperware container, we might as well think about putting the whole cannister filter inside the fridge. Isn't it about the same?

Loh K L

----------


## carlfsk

If your freezer are able to chill the water in the plastic bag holding the coil of rubber tube, why can't the water in the tupperware be chilled, as effectively? If the water within the tupperware can be chilled like those in your plastic bag, then there's a difference between just using the tube from using the tupperware.

The water in the tube is always moving fast through it. And for every cubic of it, it is covered / or separated from the chilling air by a specific thickness of rubber. Whereas in the tupperware, the water is also in constant motion. But they are only separated from the chilling air merely by a thin layer of plastic (the tub). They are also in contantly mingling with their counterparts (other cold water), which might be colder then them. In a while, they all reach equilibrium coldness before returning to the tank.

Well, these are what comes to my mind. I'm really feeling itchy to test out the hypothesis. But I'm limited by space and energy at the moment to try it out. Maybe someone who 'shares' the same passion want to take up this challenge.  :Laughing:  

Haha, putting the cannister filter into the fridge is a radical idea. Who knows, in future, the product developer can convert the freezer into a filter as well...2-in-1.

----------


## EvolutionZ

hi KL,
you mention that the temperature in the tub should be around 2 degree lower than the water in my tank. i went on to take the temperature of the water in the tub. it was 27C, totally the same as my tank.

anyway.. base on my father.. he insisted that i should just leave the pipe inside.. without the tub of water.. so i let him do it..
turn the thermostat back to 3 instead of 7 at full power..
i'll see how it goes.

----------


## carlfsk

Hi Venson, do you mind trying what I have posted? As in the reservoir thingy.

Of course, got to make sure the fridge is working fine, with good chilling power. Otherwise we won't be able to conclude anything.  :Smile:

----------


## EvolutionZ

hi carlfsk,
im still in the mids of trying out my father's method.. but my frdige is not working well. as in the cooling effect is not good.

----------


## timebomb

Venson,

Without immersing the hose fully in a tub of water, the whole system loses its effectiveness. 

Imagine this - you have a can of coke. It's warm and you want to chill it. You can either leave the can of coke in your fridge or you can soak it in a tub of cold water. Which method will cool the can faster?

But no harm will come from experimentation. Let your father try it out and keep us posted on the results.

Loh K L

----------


## timebomb

Oh, I forgot to mention....

If the temperature of the water in your bar fridge is the same as the temperature of your tank, it would actually mean you have a very efficient system. No heat is lost. But it could also mean your fridge isn't working at all.

Easy way to find out, turn off your filter. Wait an hour or two. The water in the bar fridge should become very cold, around 10 degrees C. 

Loh K L

----------


## EvolutionZ

kl,
will try the turn of filter method tomorrow. thanks

----------


## EvolutionZ

my temp is now hovering around 24 - 25C.
and the temp in the tub is 23C. which is quite ideal now after i turn off my filter for 2 hours.
thermostat is set at 2.
from 10.30 am till now. my temp is hovering around 24 - 25C.

----------


## green plant

Hi,
Anyone out there try a DIY uisng cold water dispenser? If yes pls advise how the set-up is done.
I happen to get one unit of cold water dispensor. It has a reservoir tank. Power is 60 watts. It can chilled the water in the reservoir up to 5.5 deg C with thermorstat setting at 4 (max  :Cool: . 
I want to try if I can chilled the tank to 24 Deg C. So try to get more ideas before I start.


Koh Heng.

----------


## eddy planer

Koh Heng,

That a simply good idea!  :Idea:   :Idea:  

But where do you get this cold water dispenser? i will lay my hand on it., heard that unit is a good conserve electricity!

----------


## green plant

Eddy Planer,
I got it from my company as faulty unit, leakage. Fixed the problem and now trying to get some parts to start the construction.
Similar type of unit should be availablel in Singapore. It is just an auto water dispensor with hot and cold or cold water only. You can see them in school, hospital and factories, but with various size.

Koh Heng

----------


## green plant

After reading all the post and advise from Wright, start proto type testing today.


Configuration:-
1. Tubing 22 mm OD x 1 feet length x 2 pieces
* Yes 1 feet length. No extra tubing
2. Total Volume of water : 19 ltr (plactic bucket + resservoir (chiller) + Canister)
3. Thermostart setting 4.
4. Cooler was placed next to plastic bucket

Flow of water

1. 2 x 22mm OD tubing shiphorn to Chiller Reservoir.
2. Canister filter pump water from reservoir then output to tank.

After 2 hours

1. Temperature in the tank : 22.3
2. Temperature in the reservoir : 22.3
3. Temperature of the cooling coil/ fin : 48 deg C (maximum)

Will buy some tubing and try full testing in 2x3x3 ft tank coming Saturday.

After 2 hours change Setting to 2. One hour later drop to 20.1 deg C.


Koh Heng

----------


## green plant

Hook up the system to a 3ft tank.


Water : 230 liters
Before switch on : 28.5 deg
6 hours later, it only drop by 1 deg.
When stop the filter, chiller reservoir water went down to 16 deg within 20 minutes.

So sad can not get 25 deg.

Will try to use fan and chiller system to try again. Will put on a timer in the cycle of rest for one hour for every 6 hours switch on.

----------


## mozaqua

Just my two cents on your DIY chiller.

Great idea, I thought about doing something like that myself, but I don't have the time or space. Anyway, I think you could greatly increase the efficiency by changing the hose inside the refrigerator to a conductive metal pipe like copper or aluminum, although a non-corrosive/non-toxic metal like titanium would be best. I think if you want cheap and efficient go with the copper pipe used for household plumbing. This should be non-toxic, and not leach copper into your water (which is bad for plants and inverts).
If you use a copper coiled pipe, no need to put it in the water. Just attach it to the back or shelf of your freezer, and have the water continuously flowing to prevent it from freezing. I think the temperature regulation would be much easier using the metal tubing vs. plastic. If you want it to be very accurate you could connect the thermostat to a temperature probe inside your tank, that way the fridge will kick on when the tank is too warm. A great thing about many household appliances, the schematics are readily available(sometimes inside the unit).

Regards,

----------


## timebomb

Mosiah,

I've already tried copper tubing. It causes problems. It becomes toxic and has disastrous effects on the fish and plants. Take a look at pages 15 and 16 of this thread.

Loh K L

----------


## mozaqua

Loh,

I just read your previous thread. I suspected that sort of thing would happen with regular copper tube. The kind I am talking about is coated on the inside with a thin plastic, epoxy, or even Teflon. The coating is very thin compared to your thick rubber hose, which will allow the heat transfer to the coil, where you want it. I am not sure if you can find it in Singapore or not, you may have to order it through a catalog or online. I did a quick google search but I am not sure what it is called, I have seen it in plumbing stores in the US though.
I think if you could find epoxy coated tube, it would be best for the water quality and for long term use. Teflon has good heat transfer properties, but it flakes easily, may only last a couple years before it wears off. Also Teflon coating is usually custom made, or expensive. If your only running fresh water, aluminum is cheap and effective. I doubt it would poison your fish or plants, since people use aluminum oxide sand as substrate or filter media. Although if you use it with salt water it will corrode into nothing very quickly.
Overall, I think epoxy is great stuff, inert and harmless to fish or plants. You can probably get anything coated in epoxy if you know where to find a specialty shop. Such a shop could coat your copper or aluminum tube making it non-corrosive and safe.

Regards,

----------


## PKB

Hi,

Understand that this is a 2008 thread.

Just interested to know if anyone have done up anything similar in the past 2 year? Can a mini coke (hold 6 - 8 can of drinks) fridge able to bring down the temp of a 2FT tank by about 2 degrees?

Thank you.

----------


## Eddylimst

I think copper tube and Aluminum tube also not the good choice as your cooling coil, the best meterial will be the titanium coil. Titanium is an unactive metal, thats why they are used in all the water chiller as the cooling coil.

----------


## BFG

The biggest obstacle to using titanium is cost.

----------


## Fuzzy

Those mini fridges are TEM (Peltier) cooled, making it even less efficient than TEM based inline chillers, or immersed probe TEM types.

Your best bet is a larger compressor based bar fridge, or it's likely you will spend more for the power alone over a year than the price of a chiller + power for the year.

People have used regular PVC type tubing also for the immersed coil with decent results.

----------


## marco

For those who actually made a chiller using a fridge, did you ever measure the electricity consumption using a watt meter?

----------


## sfc

> It would be great if we can group together and do a bulk order on the parts needed but I would say, let me be the guinea pig first before we start buying anything. I don't want anyone to feel let down if the thing does not work out as expected.
> 
> Anyway, I went to James' house today and took some pictures of the DIY chiller. The tank's really cold. In fact, it was so cold James had to crank up the thermostat as the thermometer was going to go below 20 degrees C. James keeps some precious show Guppies in his tank and he wasn't sure how well they take to the low temperatures. 
> 
> The idea's pretty simple really but good ideas are always the simple ones. The DIY chiller involves using either a bar fridge or a small freezer. James is using a bar fridge which isn't as economical in space and less efficient than a freezer. James isn't really interested in building a chiller for small tanks so this is just an experimental DIY chiller as far as he's concerned. His next project, a DIY chiller that can cool large tanks of up to 1000 litres is the one he's really keen on. Anyway, here's a pic of the bar fridge. 
> 
> 
> 
> As you can see, there's an inlet and an outlet pipe. It feeds directly to and from an external cannister filter which if you look closely, is at the side of the bar fridge. Using a bar fridge to cool down a tank is an idea that has been proposed and discussed many times and those who have tried it say it won't work. James made some modifications to the old idea, one of which is to replace the rubber hoses with something that is more conductive to heat. James uses PVC hoses which are flexible enough to be coiled and conductive enough to make a difference. The other significant change is to immersed the coiled hose into a tub of water. Why so, you ask? Why can't we just simply leave the coiled hose inside the bar fridge? 
> ...


 

Cool men....

----------


## nettian

up for this DIY.

----------


## marco

> Wow, 70Watts for a chiller that is so far the lowest rating I could get in the market. The lowest I know for a chiller is around 110~150w.
> 
> cheers


That Rated Power 70W may not mean its consumption is 70W. Rated power may be equivalent to cooling power. A typical aquarium/reef chiller 10hp (75W) consumes more than 240  260W.

----------


## scorpio75

welldone for this diy.
anybody using stainless steel coil for this diy mini fridge chiller? can use for 4x2x2 tank?

----------

