# General > AquaTalk >  Can a cooling fan really cool your tank?

## Shrimpong

My answer : It can and significantly, provided your room temperature is lower than the water temperature.

Contrary to what many people said and believed, I do not think the cooling fan actually 'cool' the water BUT more of influencing the water's temperature with the room's temperature. It do not cool your tank unless your room is cooler than the water in the first place. If your room's temperature is hotter, then you can be sure it will warm your water.

Before I bought the fan, I asked the seller is it effective? And how many deg change can he guarantee? Because the last thing I want is to spend $30 and not getting significant value out of it. The seller did not dare to guarantee me, in his own words "it works for some but doesn't for others so you need to try it out to know".

After trying it out for 1 week, it did not achieve significant change in temperature and was hovering between 28 to 29 most of the time which was perhaps just 0.5 to 0.8 deg lower than the original temperature.

What did change for me however is when I turn on the aircon to 16 deg and I have 3 tanks in my room. 1 x 2feet + 2 x 1foot. I used the fan on the 2 feet and the temperature dropped to 22 deg while both my 1foot tank remained at 26-27.

So does it work? Yes. Provided the air in your room is cooler in the first place because your room temperature is part of the function.

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## bigfthing

I have very different results than yours though. I set my aircon at 29C & on the fans in all my tanks. My 3ft tank will reach 26.2C & both my 2ft tanks will be 24.6C & i have a 45cm tank with a 24C.
So, i was also wondering is it lesser water volume temp drop faster? Also if this could save electricity bill as the aircon don't hv to run too cold. i think their location in the room is also critical as well as the volume of the water. However, i do turn off the aircon & leave the fans on at night for abt 8 hrs & when i wake up the temp in the smallest tank will raise the most to 26.2, same thing for both the 2 ft tanks(they are on the same side of the living room).The 3ft tank however is higher at 26.7C. No tank is near any heat source or sunlights. I am also quite curious? I just started this aircon + fan thing 3 wks so far & still waiting to see the electric bill.

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## Shrimpong

Did your CRS 'make love'(any got berried?) during this period?

My tank is placed at the opposite end of the aircon, and it managed to achieve 22-23 constantly. That is good enough for me to skip getting a chiller. 

If I have more tanks in the future, all I need is to run more fans and I could even DIY a big fan, facing the tanks top since all it need is wind blowing to create something like 'tsunami' so the water can have some sort of circulation and thats how temperature is imparted to the water.

I turn on the aircon every night anyway so it didn't cost me anything more than the electricity to run the fan.

The other method I thought of is to use large ice pack to hang at the top of the tank and change it every 12 hours. Wonder any bro tried this method before? Ice may not last 12 hours but at least the temperature would be lowered and would be last for a while...I think..

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## bigfthing

I just saw a few berried this morning. But still need to observe till i see the shrimplets.

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## Shadow

fan cooling your tank by evaporation. When water evaporate it absorb heat. It does not matter what is your room temperature is, it will drop max 3 degree from room/surounding temperature. It is also depend on the climate, it work better in dry climate because it evaporate more. This also mean that it will cool better if your house have good ventilation. Wind will cary water vapour as a result more water evaporate

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## Shrimpong

You are right that evaporation takes place. But however, evaporation do not determine the temperature. I have tried, with and without my aircon switched on and there are a lot of differences in the temperature reduction but not much differences in evaporation level.

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## Shrimpong

> I just saw a few berried this morning. But still need to observe till i see the shrimplets.


That's good to hear. I looking foward to see mine carrying eggs.

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## Shrimpong

> It does not matter what is your room temperature is, it will drop max 3 degree from room/surounding temperature.


It does. Mine dropped from 29+ to 22+ and that is 7 deg.

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## Shadow

> You are right that evaporation takes place. But however, evaporation do not determine the temperature. I have tried, with and without my aircon switched on and there are a lot of differences in the temperature reduction but not much differences in evaporation level.


first of all you are using aircon, even without fan your tank temperature probably will drop around your aircon temperature.

The question is why your fan does not work, my guess is
1) room where your tank is have poor circulation
2) your fan is too small or too slow or pointing at wrong direction
3) your other equipment such as light and filter heat up the water faster than the fan can reduce it.

if none of the above then time to scratch head  :Laughing: 

Any way there are many article on the web on water evaporation cooling effect. One good example is 
http://www.newton.dep.anl.gov/askasc...0/phy00130.htm

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## Shrimpong

> first of all you are using aircon, even without fan your tank temperature probably will drop around your aircon temperature.
> 
> The question is why your fan does not work, my guess is
> 1) room where your tank is have poor circulation
> 2) your fan is too small or too slow or pointing at wrong direction
> 3) your other equipment such as light and filter heat up the water faster than the fan can reduce it.
> 
> if none of the above then time to scratch head 
> 
> ...


I already stated that my other 2 tanks did not. It is hovering between 26 to 27 in an aircon room without fan. A 3-4 good deg off from the one with fan. And those 2 were smaller tanks too. My aircon is set to 16.

What is the lowest temp you manage to achieve with fan? And mind to share your tank size and fan brand?

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## eviltrain

normally aircon room is very dry. therefore the evaporation rate will be faster and cooling of the tank with fan will be faster and lower.

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## BFG

> The other method I thought of is to use large ice pack to hang at the top of the tank and change it every 12 hours. Wonder any bro tried this method before? Ice may not last 12 hours but at least the temperature would be lowered and would be last for a while...I think..


Google Pykrete, longest lasting ice mixture known and is easy to make and cheap too!

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## Shadow

> What is the lowest temp you manage to achieve with fan? And mind to share your tank size and fan brand?


2ft tank, temperature without fan 30 degree, with fan 27-28 degree. DIY using 2x5.5cm diameter fan, blow in about 45 degree to the water surface

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## Blue Whale

Guys, fan itself does cool off via evaporation. When looking at singapore, you would look a humidity too. Eviltrain brought out that point.

If a room is cool, so will the tank. If you stay near to vegetation, it would likewise be cooler so combined with good fan during a cool and rainy night, temperature can reach 24.7C max. It can't go down further. 

When looking at temperature change with evaporation, E.g. My Cann 3000 said 3-5C, it only achived 1C diff. I then look into the heat source. Have less heat source would then lower temperature further. Next thing is to look at wind direction. Now my house got top windows and bottom ones. Top are smaller and bottom are bigger. Usually I leave the top slightly open to allow air to flow. For 10 years, I try not to increase furniture so that air will flow freely. When looking at air flow, if front is input, back will be output so opening windows to allow air to flow out.

When looking at evaporation, do take note not to do it in the place where all your electrical stuffs are. Just a gentle reminder. Lastly, maintain your fan too so that it will work efficiently for you.

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## Shrimpong

> Guys, fan itself does cool off via evaporation. When looking at singapore, you would look a humidity too. Eviltrain brought out that point.
> 
> If a room is cool, so will the tank. If you stay near to vegetation, it would likewise be cooler so combined with good fan during a cool and rainy night, temperature can reach 24.7C max. It can't go down further. 
> 
> When looking at temperature change with evaporation, E.g. My Cann 3000 said 3-5C, it only achived 1C diff. I then look into the heat source. Have less heat source would then lower temperature further. Next thing is to look at wind direction. Now my house got top windows and bottom ones. Top are smaller and bottom are bigger. Usually I leave the top slightly open to allow air to flow. For 10 years, I try not to increase furniture so that air will flow freely. When looking at air flow, if front is input, back will be output so opening windows to allow air to flow out.
> 
> When looking at evaporation, do take note not to do it in the place where all your electrical stuffs are. Just a gentle reminder. Lastly, maintain your fan too so that it will work efficiently for you.



I heard that if one is using cannister filter, temperature will rise?

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## Blue Whale

If you ask me, my personal view is yes. How much the temperature raise would depend on the brand/model you have. Sometimes it is just how you setup. But rather than to rely on other people opinion, I advocate experience it, then learn to tackle it. But forum consist of people who do not advocate having learning curve and everything must be perfect. Most of the time, it is not the filter but the lights. Everyone is entitled to their views. I won't contest that.

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## vinz

Learning is good. Sharing experience is good. But care must be taken to post correct information and not mislead. Also good to mention when the information is based on own experience and that it is not robustly tested.

The amount that water is able to cool depends on the surroundings and many factors. Evaporation helps water to lose heat. Fans help water to lose heat FASTER by speeding up evaporation. It does that by constantly moving new 'drier' air over the water to pick up water vapour, and move that now moisture laden air away.

Many things heat up the tank water. Among them are the filter and lights. These and other factors (like ambient room temperature) heat the water up at a certain rate. The water (without fan) loses heat at a certain rate. There is a point of equilibrium which is the constant (more or less) temperature of your water.

By using fans, we help the water to lose heat faster, thereby lowering the point of equilibrium.

There are other ways to help the water cool.
1. Lowering the room ambient temperature. Air-conditioning (but not feasible for some) and good ventilation helps for sure.
2. Ventilation to ensure heat and humidity does not build up and stay in the room. Thereby allowing water to evaporate more efficiently and lose heat.
3. Placing the tank in a cooler part of the house. Example, in a room that is not heated by the sun for many hours a day. Compare the penthouse and the basement.

Basically, the point is, fans by themselves can only do so much. If the surroundings is hot and does not promote heat lost, then the fan is not going to be effective. Two key points:
- Good ventilation to prevent build up of heat and humidity around the tank.
- Place the tank in a cooler part of the house if possible. 

We can give many suggestions, but only you know the details of your set up. If you understand the key points above, you will know what you can do to help your tank lower temperature.

As for filters, my personal opinion is that does contribute to some extend. Obviously a filter which has it's motor submersed in the water, is going to heat up the water to some extend. Canister filters? Depend on their design. Do they use efficient motors and do they use materials that prevent heat build up (ever wondered why Eheim uses fragile ceramic axles in their canister filters instead of tough metal?), do they place the motor so that it minimises contact with water? Do they have a efficient heat lost design? (Compare the cheap filters that were prevalent during the Lou Han craze that have overheated and in some cases cause fires v.s. the story of an Eheim canister filter that ran dry for 20 hours without overheating (i.e. does not burn skin).)

In planted tanks, we look at temperature lost in a small range. The 'Holy Grail' 26 Celsius v.s. ambient 33-34 Celsius are only 7 to 8 Celsius apart. Even if the filter contributes half a celcius, it is a 6% contribution. Significant for some people.

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## Blue Whale

Vincent covers almost all.

The normal range of humidity for the month is 81-85% at current. I don't monitor entire year but recently been looking at weather hence, just my personal observation. I forgot whether I pm diazman or posted in his thread. Look at heat source and reduce them. From your ceiling lighting to your tank lights, to filters, to any other possible heat source such as an amplifer that is kept running. You might say its crazy but sound system are kept warm for optimum use for those who are really into that hobby.

Ok. Now for MY current setup and surroundings. I am near to Gambas vegetation, its about two bus stop length away but basically it is not blocked...at least for the moment. Direct sunlight as seen by Aquanoob, Wackytpt, Edmund, Reveru, etc. during day time. Just happened to drive past my house during the outing.

*Ceiling centre* - 20W 6500K circular (small)
*Ceiiling left right* - 2x 10W Osram Dulux D. These are part of the 6 small lights around my living room. Saving money and still keep cool and keep my greenish (cyan) colored living room lighted. Planned this 10 years back, been saving a lot of electricity on this setup. Got another 2x32w 6500K circular lights in the centre of the living room. Its L shaped. So the tank is located at the short L. There are 2 center.

It is a bit humid now, so I just took the temp shot so you can see. Lights just off about 46mins from this post.

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## mordrake

why your 2 x 1ft does not cool down to a lower temp?

1. less surface area for heat exchange
2. rate of heat loss slower due to lack of wind assistance i.e. the fan.

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## jssl

Just bought a cooling fan (brand - Water Plant) for my 2ft tank. To my surprise, temperature dropped about 3 degree Celsius within 4 hours. 
The only setback is the wind noise. The fan motor itself is quiet enough.
Anybody can suggest how to reduce the wind noise?

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## Fuzzy

Actually for me the main problem with fan cooling isn't the noise..it's the evaporation.

It was pretty brutal on my 3ft tank when I was fan cooling it, it dropped temps from 30C maximum to 27C maximum, but i was topping up about 25L of water every 3 - 4 days, and it was leaving seriously stubborn water stains along the water line.

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## bigfthing

I think the fan still lacking that 1 to 2 degree celcius, so now i move all the shrimp tanks into a smaller room & turn on the air condition 24 hours! Damage is $170 extra in electric bill per month. Oh, i have them in the living room before & turn on aircon set at 29 degree C plus fan for all tanks to bring down to 25 degree C. Now i think easier in the smaller room, i leave the air con on auto & the temperature seems more constant at 23 to 25 degree & less water evaporations!

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## Shadow

with extra $170 a month, it better of with chiller. How big is your tank by the way?

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## bigfthing

haha...2x 2feet, 1x1.5feet, 1xnano, 2x 4feet(setting up this week) & the rest are in the living room. Chiller cannot chill so many at one time & chiller tank got a lot of moist water outside of tank & creates heat in your living space as well. I quit smoking for the extra electricity bill! And quit drinking for this hobby! Worth it!!!

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## Shadow

which so many tank, aircon probably cheaper ... :Laughing:

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## jssl

So can I say for a 2ft setup with eheim 2215, hailea HC100 or ReSun 280 is adequate?

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## Tamama

> So can I say for a 2ft setup with eheim 2215, hailea HC100 or ReSun 280 is adequate?


Go for resun cl280 in case u may wanna upgrade to bigger tank.  :Smile:  small chiller also a bit hard to sell it off as most people use chiller for bigger tanks.

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## Fuzzy

> So can I say for a 2ft setup with eheim 2215, hailea HC100 or ReSun 280 is adequate?


I would recommend going with the Hailea HC-150A instead of the HC-100 or CL-280.
I've had better experiences with Hailea than Resun personally.

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## jssl

Its true that Cooling fan can only bring down the temperature 3 to 4 degree celsius. I guessed it all boils down to the ambient temperature and humidity.
Surprising, once I off my cooling fan, the temperature went up to 32 degree celsius again. It must be due to my 2215 cos ambient temperature don't think is 32 degree celsius.

Anybody got idea how much is Hailea HC150A?

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## eviltrain

> I quit smoking for the extra electricity bill! And quit drinking for this hobby! Worth it!!!


i already quit drinking for this hobby. haha. about the smoking part, once a smoker always a smoker.  :Opps: 

i'm now running my resun cl450 on 2 numbers of 2x1x1 feet tank. soon will link another tank together. insulation tube and Styrofoam board to prevent further heat gain.

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## felix_fx2

> i already quit drinking for this hobby. haha. about the smoking part, once a smoker always a smoker. 
> 
> i'm now running my resun cl450 on 2 numbers of 2x1x1 feet tank. soon will link another tank together. insulation tube and Styrofoam board to prevent further heat gain.


Quitting to drink is easier then to quit smoking.
My smoking with my current job is 1\2 as much as it used to be.

This is very mental question, Fan VS Aircon.
I think vinz has more or less said all.

It all boils down to, Budget=fan no budget=aircon/chiller.

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## eviltrain

yapz i agree, but i do cut down on smoking when i'm busy messing with my tank or tying fissden or other mosses. 
3 hours on net at night = 3-4 sticks
3 hours on my shrimp tank = 1-2 sticks 
hahaha

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## Shrimpong

> yapz i agree, but i do cut down on smoking when i'm busy messing with my tank or tying fissden or other mosses. 
> 3 hours on net at night = 3-4 sticks
> 3 hours on my shrimp tank = 1-2 sticks 
> hahaha


That means you are bored that's why smokes. Tie more fissden or moss. Once your mind is occupied you will forget about smoking in no time.  :Smile:

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## Tamama

> Its true that Cooling fan can only bring down the temperature 3 to 4 degree celsius. I guessed it all boils down to the ambient temperature and humidity.
> Surprising, once I off my cooling fan, the temperature went up to 32 degree celsius again. It must be due to my 2215 cos ambient temperature don't think is 32 degree celsius.
> 
> Anybody got idea how much is Hailea HC150A?


290 from the lfs at thomson, not sure about others.

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## dannyfish

> Just bought a cooling fan (brand - Water Plant) for my 2ft tank. To my surprise, temperature dropped about 3 degree Celsius within 4 hours. 
> The only setback is the wind noise. The fan motor itself is quiet enough.
> Anybody can suggest how to reduce the wind noise?


hello 

May i know where you buy your fan and how much huh?..drop 3 degree seem quite effective..may i also know how you place your fan?
Thank

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## chumzhujun

how i wish singapore is at the other side of the world... they buy heater which cost 30 we buy chiller for300plus.....

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## dkk08

Anyone has experience with a blower instead of a fan? If you do not know what I'm talking about, think car/bus fan elongated blower, I've seen folks in USA and Europe DIYing them for their tanks... wonder if we can find them here?

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## Shadow

> how i wish singapore is at the other side of the world... they buy heater which cost 30 we buy chiller for300plus.....


you wont said that if you know how much flora and fauna cost over there  :Wink:

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## Terrible

My experience is the fan works.
My living room is airy. I always have my windows ajar. 
I don't have air conditioning in my living room. 
With the fan, even on regular day time my water temperature can go down to 26-27 celsius. 
It's about 2-3 degrees drop. 
I run the fan 24/7 minus a 15 minutes rest on each knock on the hour hand. 
So yes it works. 
BTW fan doesn't blow the water to cool it. 
It is accelerating the rate of water evaporation.
Evaporation draws heat out from the liquid. 
I had to top up water almost every other day with 5 litres into the aquarium.

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