# Other Aquarium Forums > Fish Care, Nutrition and Water Management >  pH and RO water

## beachkrazd

Hello there! This is my first time posting on any kind of fish forum. My LFS has done a good job so far of helping me start a planted tank and I have done a LOT of reading online about various topics, but now I need some outside advice concerning RO water.

*My main question is:* Is it normal for the RO water from the LFS to contain KH 10 degrees and GH 11-12 degrees? Shouldn't the levels be near zero? Could something be wrong with the RO filter at the LFS? I have been adding Kent RO Right to replace minerals to the 'supposedly' 'pure' RO water. Do I need to add RO Right if there is already KH and GH present in the RO water? 
*
Second question:* Based on the different KH values in my 29 gal (KH 6) and 10 gal (KH 11) tank, does this mean I should continue using Kent RO Right? 
**EDIT** I just saw the the GH is higher in my tanks than the RO water, which indicates I'm raising GH unnecessarily by adding Kent RO Right. Oddly, KH is lower in the tanks but I think I read plants can lower KH.... 

*Third question:* Why is the RO water causing the high pH of 8.4 in my 10 gallon tank? The pH of RO water straight from a sealed container is 7.2-7.4 but if the water is allowed to 'age' the pH becomes 8. The pH in my 29 gallon tank is 8. I thought the RO water would cause my tanks to have a lower pH. 

The tap water here is very hard (dKH 13, dGH 18 with nitrates ~5-10ppm and a pH of 8 so I decided to use RO water since it was cheap and I _thought_ it would solve my pH and hard water problems. 

(All parameters measured with API dropper kit. I just bought the KH/GH dropper kit so I'm new to understanding those test results.)*

RO water from LFS:* 
KH 10 degrees = ~180ppm
GH 11-12 degrees= ~200ppm
-are these KH/GH values ok for non-treated RO water?
 pH straight from sealed jug - 7.2-7.5
pH after sitting out for 12 hrs - 8

*Tank parameters:
29-gallon* *tank* - started this past summer
-*Water source:* RO water from LFS, I use Fritz Guard chlorine remover and Kent R/O Right 
-Ammonia/Nitrite 0, Nitrate never more than 20, typically 10-15
-pH 8
-KH 6 degrees = ~100ppm
-GH 14 degrees = >200ppm 
-DIY CO2 (one 2L bottle)
-Moderately planted with Vals, Crypts, Java fern, Hygrophila siamensis and Anubias nana
-a broken clay pot is in the tank which supposedly should not alter pH
-*Occupants:* 6 lemon tetras, 3 neon dwarf rainbowfish (1M:2F), 2 apple snails 
-*Substrate:* Flourite 2-3" deep
-*Filtration:* Aqueon stock 29 gal kit with sponge filter on intake tube
-*Cleaning regimen:* weekly 15-30% water change and gravel vacuuming, rinsing of sponge prefilter (3 or 6 gallon bucket change)
-*Feeding:* I was picking up a lot of fish waste in the gravel during weekly cleanings so I cut back on feeding from once a day for 2 minutes to once a day for 1 minute. (I literally use a timer.) 

*10-gallon tank* (started about 4 months ago) 
-*Water source:* same as above for the 29 gallon tank
-pH ~8.4
-KH 11 degrees = ~200ppm
-GH 15 degrees = >200ppm
-Ammonia/Nitrite 0, Nitrate 10-15
-no CO2 injection
-One small piece of a broken clay pot
-*Substrate:* 1-1.5" CaribSea natural white moon sand (pH-neutral) (I do stir the sand with every water change; my Val roots go crazy in this sand!)
-*Filtration:* Aqueon 10-gal kit stock filter with sponge pre-filter on intake tube
-*Occupants:* 3 Corydoras habrosus, one Apistogrammoides pucallpaensis 
-Moderately planted with Vals, java fern and Anubias barteri
-*Cleaning regimen:* Weekly 30% water changes with RO water + Fritz Guard + Kent RO Right
*
I greatly appreciate any advice that you all may have!*

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## Cross

ro water gh 0 kh 0 .Think your lfs's membranes are too clogged. only add supplements to pure ro water

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## blue33

If your water is too hard, you can add a softener resin(if i remember correctly) after the RO equipment to softer the water before introduce the water. Those are in brown colour.  :Smile:

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## beachkrazd

Thank you Cross and Blue33 for your responses. I'm really disappointed that my LFS has been selling me barely-watered down tap water as RO water AND then convincing me that I need to add Kent RO Right to it. I guess they don't ever monitor their RO output. 

I asked the LFS about my high pH today (before I had tested their GH/KH) and they made light of it. I knew something wasn't right when everywhere online says the pH of pure RO water is fairly low, not usually 8, but again the LFS acted like it was normal/fine. I'm afraid I may face some resistance when I approach them about the high KH/GH in their 'RO' water, but if they want to keep my business they better be receptive to my concerns.

I visited the Culligan machine at the local Wal-Mart and its water has a pH (non-aged) of 6 and KH/GH of zero for 27cents per gallon. The machine is checked monthly for water quality and the maintenance person has to sign off on a little log that's visible for all to see. I'm thankful for the quality assurance measures taken with their product. Looks like I'll be getting my water from Wal-Mart unless the LFS fixes their RO filter. I hope the aged Culligan water has a pH close to 7, that would be awesome!  :Grin:  Since Wal-Mart is open 24/hrs I won't have to worry about not having water available for an unexpected late-night emergency water change.

I feel like I'm very close to achieving stable, ideal water conditions! Yippee!!  :Jump for joy:

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## beachkrazd

Today I mixed 50/50 RO water with my hard tap water. I thought this would be easier than messing with chemicals to treat the RO water by itself. Initial pH of the mix was 6.8 but I knew with some aeration and 'aging' the pH would increase somewhat as dissolved gases (CO2) from the tap water were allowed to escape and equilibrate. 

*Initial pH of 50/50 mix* 6.8
*Current pH** 7.2 (vs. pH 8 with tap water alone)
(*after placing a bubbler in the bucket for about 1 hr)
(pH may increase a bit more as the water continues to 'age' but as long as it stays in the 7's I'll be happy)
*dKH* 8-9 (vs. 13 with tap water alone)
*dGH* 10 (vs. 18 with tap water alone)

So far I'm very pleased with the results. I think with the 50/50 mix I should be able to achieve fairly stable, optimal water conditions. 

*Question:* Now I just have to _slowly_ acclimate my fish to this new mixture of water. I'm thinking small, _slow_ 10% water changes over the next few days/weeks with the new 50/50 mixture. Would that be ok? By 'slow' I mean pouring in a little bit at a time, not just dumping the full 10% at once. The tank parameters are dKH 6, dGH 14, pH 8, which overall isn't (too) drastically different from the new 50/50 mix other than the pH difference.

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## stormhawk

You might want to try and keep the pH around 7 just in case. Maybe reduce the mix of tap water to RO water. Try 60% RO to 40% tap water. You'll probably have to add in some commercial mineral mix if some minerals are missing from your tap water. This is more for the growth of some inverts like shrimps and the sort.

Use the drip method to let the new water flow into the tank slowly. You can probably DIY a dripper using a inverted Coke bottle with an airline out of the bottle cap and ending in a valve to adjust the flow rate. 

It's similar to a DIY brine shrimp hatchery, except you're using it to drip fresh water into the tank. A slow steady drip flow into the tank should not cause too much stress to your current inhabitants.

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## beachkrazd

Thanks for the advice Stormhawk. :Smile:  I think the final pH with the 50/50 mix was 7.2, but technically I didn't wait for a 12-hr reading. 

Tonight I'm testing 60/40, RO/tap water. KH and GH went down by 1-2 degrees compared to the 50/50 mix but still within an acceptable range. I've looked up all of my fish online and they should tolerate these parameters so all is good.  :Smile: 
*dKH:* 7
*dGH:* 8
*pH:* to be determined tomorrow, but initially was 6.8 (same as 50/50 mix)

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## Fuzzy

Have you considered buying a small RO/DI system? 

They are fairly inexpensive, and will be cheaper to run long term than buying RO/Distilled water from stores.
Additionally you'll have the assurance the water is clean and pure.

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## fish_bone

Sorry to drop in the conversation but I just want to know how much a small RO/DI would typically cost? I used to use tap water with simple strainer from ACE hardware but I'm having bad algae attack now. I started using filtered water from my kitchen (HEXAGON filter) last week but carting the water from kitchen to living room is breaking my back. if RO/DI is affordable, I will buy it.

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## beachkrazd

> Thanks for the advice Stormhawk. I think the final pH with the 50/50 mix was 7.2, but technically I didn't wait for a 12-hr reading. 
> 
> Tonight I'm testing 60/40, RO/tap water. KH and GH went down by 1-2 degrees compared to the 50/50 mix but still within an acceptable range. I've looked up all of my fish online and they should tolerate these parameters so all is good. 
> *dKH:* 7
> *dGH:* 8
> *pH:* to be determined tomorrow, but initially was 6.8 (same as 50/50 mix)


OK, the *pH* of the 60/40 mix is about 7.5 after 24 hrs of aging. Honestly, it was really hard for me to interpret the exact pH due to slight color variations and the fact that the intervals given on the color code are in even numbers (7.4, 7.6 etc.) so I could say the pH is anywhere from 7.4 to 7.6. (Apparently my 7.2 reading of the 50/50 mix was premature.  :Sad: ) 

*Question:* Is it normal for the pH to range from 6.8 to 7.5 in just 24 hrs? Does this mean that aging our water (or at least my RO/tap water mix) is more important than we thought? Or could my RO/tap water mix just be different somehow?

I looked up my remaining fish online (Lemon tetra, Dwarf Neon Rainbofish, and a Betta) and all should tolerate a dGH of at least 5 degrees. So I guess I can dilute the tap water a bit more to try getting a lower pH. 

*Buying* *an RO filtration system:*
Right now my income is somewhat limited and I'm still in the early phases of experimenting with RO water for my tanks. I'm content for now with waiting for a better time to invest in it. I graduate in May so money may not be so scarce after then. :Grin:  Whenever I am ready to upgrade to RO filtration I will probably buy one from this list:
http://saltaquarium.about.com/od/top...prodiunits.htm. Any thoughts about any of these systems would be welcome. :Smile:

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## beachkrazd

**Edit** This website (click here) I just found tonight describes what I'm trying to do by mixing RO/tap water. I wish I had found this sooner so I would have known that I'm on the right track. :Smile:  

Now testing 80/20 RO/tap water mix. (I decided on this ratio before I found the cool ratio formula on the website mentioned above.) 
Initial parameters:
*dKH:* 4
*dGH:* 5*
Initial pH:* 6.5
*24hr pH:* to be determined tomorrow

I'm not going to use an air stone at all during the aging process this time since I may be promoting more gas exchange (CO2) than is necessary by doing that. Plus there are no airstones in the tank so 'natural' dissipation of gases over 24 hrs will simulate normal tank conditions.

I like the KH and GH with this ratio so whatever the aged pH turns out to be (I'm trying not to be too obsessed about it :Grin: ), I will probably continue using this 'formulation' (unless someone knows a reason not to). :Smile:

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## blue33

You can try collect rain water(quality depending on places also) and pass through those RO system and see what parameters you can get rather from the tap water. IMO  :Smile:  Those marine use RO/DI system in USA should be cheap and good.

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## stormhawk

Using rain water can be risky at times, especially in areas affected by acid rain.

As for pH measurement, the color coded ones can be tricky for some people, so using a good pH pen will be much better. 

The weblink is great though. Since your initial pH reading for the 80/20 RO/tapwater mix is at 6.5, I think you can stick with that. At least if it goes up the scale to around 7, the change should be gradual enough that the fish won't be too affected by it.

@fish_bone:

blue33 has a point though. Buying your own RO/DI unit for home usage might be good. Some discus breeders, marine fish hobbyists in the US rely on them. The cost varies from setup to setup, depending on what you want from it. 

I don't use any though, since in Singapore the tap water is good enough depending on where you are living. The problem for us here is how to control the chloramines still present in the water. Dechlorinators is the shortcut, but I'd rather use activated carbon in small tubs to remove them slowly. A tapwater filtration unit might be useful as well.

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## beachkrazd

The pH of the 80/20 mix is 6.8-6.9 after about 19-20 hrs. I guess using an airstone for 1 hr during the 24hr aging significantly increases gaseous exchange because the pH of the other mixes increased much more dramatically over night (for example from 6.8 to 7.6 vs. 6.5-6.9 this time). My plants will use the dissolved CO2 while it sits in the tank so the pH may naturally increase somewhat between water changes.

I guess I will continue to use this mix. Now if only I can convince my LFS to fix their RO system so that it will be much more convenient to purchase the RO water (they carry the jugs out to my car :Smile: ). And someday I will probably invest in my own RO system.  :Grin: 

Thanks for the input Stormhawk! Wow, I looked up digital pH meters and they were a lot more expensive than I thought they would be. No wonder most people just use the liquid tests. :Smile:  The two that I found were about $200, putting them in the same price range as an RO filtration system. Unless there are some which are significantly less expensive I will just have to make do with the liquid tests.

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## stormhawk

There are cheaper hand-held ones from Hanna and Milwaukee Instruments. You can probably get one for cheap + shipping off eBay from a trustworthy seller, or any of the marine LFS in your area. Some online stores sell them too. They are not that expensive to purchase unless they have some sort of extra additional functions like measuring TDS etc.

What is more crucial is the need to calibrate the hand-held pH pens regularly with the use of calibration solutions that are fixed at a certain pH. It's not too expensive, and sure is more accurate that using a test strip or liquid test kits.

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## Fuzzy

You could consider going with straight up DI water, RO is seriously overkill for freshwater applications, IMO.

I am actually using DI filtration for my freshwater and marine tanks, many reefers also go this route as the waste water from the RO process and the how slow the RO process is, may not be so palatable to some.

For lower volume aquariums (under 30 gallon) it should be fairly economical to go this route. Also if you're handy and have experience handling chemicals you can recharge the DI resin yourself

http://www.marinedepot.com/reverse-o...ticals-ap.html

http://reefkeeping.com/issues/2008-09/nftt/index.php

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## beachkrazd

I found a more reasonably priced pH monitor that has fairly good reviews, *American Marine Pinpoint pH Monitor Package* (on sale for ~$104). I may consider buying this one in the near future. I found a few other pH meters that were cheaper but they usually had poor user reviews. http://www.marinedepot.com/American_...MOID-0-vi.html

I'm in the process of researching DI water filtration, trying to figure out how DI water is different from RO water. I will definitely consider using it when I buy my own filtration system.

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## beachkrazd

I was hoping someone can verfy deionized water for me. Please let me know if any of this is incorrect:
DI water has zero KH and GH and lowers the ph to about 5.5 or 6.5. Is this true? So I could mix di water with high ph/gh tap water to achieve soft neutral water, right?

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## Fuzzy

I soak coral chips in my DI water aging drum, so it reads pH 7.0 after I let it sit for a day. I've tested the output water directly and it was pH neutral also though.

It does read as GH and KH 0 though.

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## stormhawk

pH monitors are not a necessity IMO. Those hand-held versions aka meters are usually more value for money, plus they're easy to use. Just dip and get the reading. American Marine is a fairly good brand, but where hand-held sets are concerned, I usually trust Hanna.

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## Fuzzy

I use mainly Hanna and Milwaukee instruments myself. But yeah I agree a pH monitor is overkill for a small freshwater setup.

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## beachkrazd

Just a quick update. I realized that GH 5 with 80/20 RO/tap water mix is probably too soft for my Apple snails. I've noticed that their shells are not as smooth as they used to be. I'm going to try the 50/50 or 60/40 RO/tap mix to get GH around 10, which should still be fine for the fish and plants. It's still probably more tolerable than GH 18 with plain tap water.

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## Blue Whale

> Sorry to drop in the conversation but I just want to know how much a small RO/DI would typically cost? I used to use tap water with simple strainer from ACE hardware but I'm having bad algae attack now. I started using filtered water from my kitchen (HEXAGON filter) last week but carting the water from kitchen to living room is breaking my back. if RO/DI is affordable, I will buy it.


Fish Bone,
Would you not consider to start a new thread? The guys are troubleshooting for beachkrazd at the moment.

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