I've read the non-CO2 articles, I don't do water changes ,just top off for evaporation. I did this tank for a friend but I don't know how much he feeds the fish. The dosing is every 3 days, Flourish excel,Flourish, Seachem Potassium and Nitrogen. I might add CO2 injection but I want to try out the low tech way of no CO2 injection.