ph 7

Question is in bold and underlined, the rest is explanation. I just put in a 2 400gpd RO membrane system in my basement mainly to use for my tank top off and water changes but I also piped in three refrigerators and a few drink fillers throughout my house all ran off of a 30 gallon RO pressure...

Quick question guys. My ammonia, nitrite, was zero, nitrates were in the usual range, ph a little low. Did WC, added ph buffer to bring ph to 8.2 , ammonia 0, nitrite 0. Added 4 new fish. The ammonia increased to .25, fish were doing fine, I was adding fritz turbo 900. The nitrite was still 0...