dwarfguy
10-31-2015, 05:09 PM
I know this has been talked about alot, but soft water is more a factor of tds, or really dissolved mineral content than pH, kH or gh. For general fish keeping purposes the necessity of soft water can be debated, when it comes to breeding I know I see a correlation.
So, what I am getting at is I use RO to remove minerals. Adding minerals back that just don't show up with a standard test kit seems self defeating. I don't know what fish need in their water, but if you look at seriously fish.com and see what the waters they come out of are, it would appear to be very little. I don't know what is absorbed through the environment and what is taken in through diet. I do know that freshwater fish take in water through osmosis, anything else I can't comment on.
Next, as ro systems get used, a certain amount of junk gets through. With my water and water pressure I get about 20 gpd out of a 100 gpd system. As the membrane and resin age, both output and purity decline.
Last, for reasons unknown to me, adding my hard water back to ro water doesn't automatically give me alkaline water. Without knowing the chemicals and concentration I don't know that you can come up with a formula to tell you how much to use - and that is were using packaged chemicals can help, but I don't believe it to be necessary. Knowing that pH is a negative logarithm of H+ ions doesn't tell you what to do if you have a target pH.
So, what I am saying is, I don't know of a reason to use RO water for freshwater aquariums other than to remove as many minerals as possible. Once removed I am not convinced of the need to add them back for the fish`s sake. And last, although ideally RO/DI water should be close to pure, in practice it isn't necessarily true.
So, what I am getting at is I use RO to remove minerals. Adding minerals back that just don't show up with a standard test kit seems self defeating. I don't know what fish need in their water, but if you look at seriously fish.com and see what the waters they come out of are, it would appear to be very little. I don't know what is absorbed through the environment and what is taken in through diet. I do know that freshwater fish take in water through osmosis, anything else I can't comment on.
Next, as ro systems get used, a certain amount of junk gets through. With my water and water pressure I get about 20 gpd out of a 100 gpd system. As the membrane and resin age, both output and purity decline.
Last, for reasons unknown to me, adding my hard water back to ro water doesn't automatically give me alkaline water. Without knowing the chemicals and concentration I don't know that you can come up with a formula to tell you how much to use - and that is were using packaged chemicals can help, but I don't believe it to be necessary. Knowing that pH is a negative logarithm of H+ ions doesn't tell you what to do if you have a target pH.
So, what I am saying is, I don't know of a reason to use RO water for freshwater aquariums other than to remove as many minerals as possible. Once removed I am not convinced of the need to add them back for the fish`s sake. And last, although ideally RO/DI water should be close to pure, in practice it isn't necessarily true.