I have nerites multiplying like rabbits in a 40 U.S. Gallon high tech tank with pH 6.4-7. CO2 injected, two Kessil A160we full intensity 10 hours/day, 50% intensity/70 % color another 4 hours/day, densely planted with crappy white sand substrate, EI dosing. I can't give enough nerites away but they keep that tank and three more FW I have spotless. I am moving 8 hours away in 2 weeks and will sadly be breaking down all of my tanks and keeping as many nerites as I can. Oh, other parameters: KH 9 and pH in between 6.4 to 7.2. Charts don't give the correct CO2 concentration though, otherwise fish would be belly up with the CO2 concentrations they give.... DC stays lime green... GH is supplemented with Ca++ and Mg++.