What's making my water hard?
I don't get it, I use 3/4 RO 1/4 tap water for my weekly water changes. RO has a PH of 7.2 & tap has a PH of 8.0 and the PH of my water comes out to be between 7.4 & 7.6. I have a 12 gallon tank that I apply the same portions of water and it has a PH of 6.8.
Both tank are injected with CO2, I use Red Sea Flora Base which SHOULD maintain the water slightly on the acidic side. I have 2 small pieces of dirft wood. I don't have a stones in my main tank but I use several small stones in my 12 gallon tank and yet it has a lower PH.
The only thing that I could think of is K2SO4. I dose according to EI but I kind of overdose K2SO4 (not a lot though). Is this causing the PH to rise? I'm dumb founded. Does anyone have any idea whats happening here?