Have been raising fish off and on for 50 years and only have used well water and city tap water. I have come to the conclusion that city tap is a pain in the butt. The PH is like 8.6+. So I decided to use reverse osmosis four staged water. Everything is taken out of it. So is there something I should know about the electrolytes and minerals needed for freshwater fish? I only started to use it when doing my water changes, so is it necessary to add something different? Second question: If setting up a new aquarium with RO water, is it necessary to cycle? There is no chlorine, ammonia, nitrates or nitrites in it. And again what do you add to it? I can't find it on the net anywhere.....
Anonymous2012-03-03T20:51:22Z
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Yes your tap water does seem a bit high ph and probably hardness. Enough to give you issues with many fish and plants anyway.
Using PURE R/O water however is not a good idea, it has zero hardness, no buffering to keep the pH stable, and no trace elements. Using that will create a whole different set of problems.
What I suggest you do is mix "some" of your hard tap water into the R/O water, to give you a sensible pH and hardness, and use that. You will need to experiment on the ratio, but if your tap water is that hard maybe you will only need 10 or 20% tap water mixed into the R/O to get sensible water parameters for most fish.
RE: Using reverse osmosis water in aquarium? Have been raising fish off and on for 50 years and only have used well water and city tap water. I have come to the conclusion that city tap is a pain in the butt. The PH is like 8.6+. So I decided to use reverse osmosis four staged water. Everything is taken out of it. So is there something I...
First off, R/O water is not mineral water, it's the opposite, its Non-mineral water. The R/O filter removes most of the pollutants and minerals from the water, thats the idea of using one. That leaves the water practically pure, but it has no hardness or pH buffering, and no trace elements. So if you want to use it for your tank you should add some buffering (a product called RO Right for example). This restores the correct level of hardness and trace elements to the water. If you are using an R/O unit because your tap water is very hard, but otherwise clean then you can just mix a bit of normal conditioned tap water back into the RO water to get the hardness and PH back to normal levels. Maybe 10-20%? Using R/O for a pond is probably going to be overkill, and it depends on the quality of your tap water as to wether you need it at all. If your tap water is clean and reasonable hardness, then it's perfectly OK for fish as is. Ian
First of all most modern day fish breeders use city water which can typically range from 7.5 to 8.5. The fact that some people use RO water can actually stress the fish because they were bread in higher PH water. Ask your local fish store to test the ph in their tanks...I suspect they will generally be around 8.0. That being said I would stick with city water and use tap water conditioner. Even in the wild; most rivers, streams lakes etc are alkali.
Another CON of using RO water is the need to add trace elements to your water - like calcium, magnesium etc. This can (and will) likely be more if a pain than using city water and conditioner.
It is ALWAYS necessary to cycle a new tank. The idea of cycling a tank is to produce ammonia, nitrates and nitrites so that the beneficial bacteria that feed on these harmful chemicals can propagate and live in the biological filter media in your filter system. Once that is done then the fish by products (fish feces) that will inevitable end up in the tank will be quickly neutralized by the beneficial bacteria made during the process of cycling.