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anyone using pure RO water....?

5707 Views 30 Replies 11 Participants Last post by  BuckeyeFieldSupply
with Co2 injection? is this possible??
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Absolutely! I use straight RO/DI currently, ran 24x7 co2 for about 6~7 months up until 2 weeks ago and never did I have any gasping fish, PH stressed, KH stressed or any other kind of stress for that matter. Oh BTW I never experienced the dreaded ph crash either :rolleyes:
yeah but with no buffering capacity didn't your PH crash?? RO is pure water where was the KH coming from? what did your PH drop To? my RO water is about 7 - my tap water is near 9? i'm freaking out here right before setting up my tank beause i really can't grasp the KH PH Co2 relationship.

thx, john
I wouldn't be too concerned about your pH "crashing," so to speak. The thing is, adding CO2 might make the CO2 reading go down, but it's not really hurting your fish (provided you have soft water fish. African cichlids might not be pleased.) However, if you do use straight RO in a planted tank, I'd be more concerned about the lack of minerals for your plants. You need to either mix with tap or remember to dose traces. Sometimes, people dose gH booster just so the plants get magnesium and calcium and stuff like that.
I use RO/DI as well, and do not add anything that increases KH. I have never experienced a problem with fish, shrimp or snails. I have never had a pH "crash." I do add Seachem Equilibrium to bring the GH up.
Pure RO Water

Not to much stuff will survive in pure RO water.
Whatever is say here...

Shrimp need calcium and everything else
Fish and plant need some nutrient, minerals

What do you want to try?:icon_ques

Pure RO water PH 6 to 6.5
add CO2 (acid carbonic) around 4.8
no carbonates to buffer solution

equal catastrophic result and plunging PH

Try to have goal for your water parameters based on the natural habitat that you want to reproduce and find the most easy way (whitout playing chemistry) ex: RO = tap water = what you want.

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IMO the best thing to do is start with pure perfect water(RO). Then from there adjust by running the water through peat or aragonite or whatever environment you are attempting to recreate. I use pure RO water. I have a planted tank and an african cichlid tank. Both work quite well, with no bad effects from the RO. For a buffer in my planted tank I have a small bag of aragonite from my cichlid tank added in my filter. This increases the hardness naturally and it stays stable, as opposed to dosing some sort of buffer every day or every week. In addition to being a good base, I truly believe that some "quality H2O" is the best thing you can do to get the most and best out of your fish. Using tap water for your tank is the equivalent of people breathing in smog filled air. All kinds of ill effects are going to happen. Thats my .02.
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I'd start with RO no matter what if you have the option. It's easier to put stuff in then take stuff out. I don't agree that tap is necessarily contaminated, it is just that many species we keep come from south american environments that have soil with some of the lowest mineral content on earth, thus having water with very low TDS and pH.
RO/DI is a little over 99%. Nothing can live in totally pure water, you are right, but most species are perfectly happy in straight RO/DI.

I did it when I was keeping the very rare difficult species. Hell for a while when my R/O broke I used distilled. No problems.
do u guys w/ ro make the big 50% weekly water change?

I'm using 1/2 RO but my tank is 200 gallons. That's a LOT of water wasted to make that much RO each week.

I'v cut my water changes back to 50 gallons a week. So far everything has been fine.
I use RO/DI and do 50% each week and a 90% every 4~6 weeks but I have a 90gal though.
I have a 65G african cichlid tank and a 29G planted tank and I use pure RO in both on water changes. 50% on the planted 1x per week, and 30% on Sundays plus 5 gallons every other day on the cichlids. All of those are done with RO only.
My wife is bitc*in at me about all the water I'm using!! RO is like 80% waste and 20% ro output. Changing 100 gallons a week meant using about 500 gallons of water a week.
For a while our water meter was broken and I got a way w/ it. now that she sees the numbers, Im cut off :(
80/20? What kind of RO unit do you have? Mine doesn't seem to be that bad. Plus I just run the waste line outside and into a flower bed. Makes it feel less like waste :icon_wink . I have a 55 gallon "Brute" trash can(the kind on wheels) and I fill it up on Friday (takes about 12 hours) then I refill again on Sunday. I do a WC on Sat. and another on Sun. It works out pretty well. The water from my tap is pretty nasty (look up "trihalomethane") so I actually use the RO as drinking water too. I never really noticed a large jump in my water bill though. Maybe its just the unit you have.

Use the amount of RO water you want until the parameters of the tank are what you want at the end.
Actually I googled RO waste percentage before I made that post. 75% waste to ro seems to be the norm. I exaggerated a bit to 80%.
AND, I did find a problem w/ my system which is adding to my water usage. It never shuts off! It slows significantly when it should be off, but doesn't stop draining. It's about a year and 1/2 old, so I think I'll get a new system. It was a cheap ebay system. It costs almost as much to replace the filters as it does to get a new system. I did try replacing the pressure valve and that didn't fix the constant draining.

I'm not trying to stop anyone from using RO. I'd use all the water I want if it wasn't for my wife. She's a LEED certified architect (LEED is all the Green Building stuff) and is very aware of things like water usage. (too aware of things like water usage ;) )

here's an excerpt from one of the pages I found... Many others say about the same thing..

Disadvantages of reverse osmosis units

RO units use a lot of water. They recover only 5 to 15 percent of the water entering the system. The remainder is discharged as waste water. Because waste water carries with it the rejected contaminants, methods to re-cover this water are not practical for household systems. Waste water is typically connected to the house drains and will add to the load on the household septic system. An RO unit deliver-ing 5 gallons of treated water per day may discharge 40 to 90 gallons of waste water per day to the septic system.
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Hmmm... Guess you learn something new every day! Thanks for the info. Do you have a solenoid on yours? (The 4x thing)

Mine fills a 3 gallon tank and when thats full it shuts off. Then I fill a cup of water and it fills that back into the tank. If not in use then its not running/making waste.
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Not to much stuff will survive in pure RO water.
Whatever is say here...
Where do you get your info? Nothing could be farther from the truth.
Far from the truth???

Where do you get your info? Nothing could be farther from the truth
Do the test, trow discus, plants and shrimps in a RO tank... No nutrients, small amount of food, 40 to 50% RO water at weekly water change and everything die...

You can use RO to replace evaporation, or to lower your buildup of nutrients but not as an environment for living organisms.
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