Hello all. I, like many, use the python vacuum hose system to change the water in my tank. I am currently on well water that has 0 Ammonia, Nitrites and Nitrates and a PH of 7.2. We will soon be switching over to the city water supply and will then be getting lord knows what kind of chlorine and flouride treated water. I was wondering what everyone with city water does when adding water through the python hose? Is it ok to do a 10% change and then add chlorine remover? Or is that still too much stress on the fish for that brief time? I am guessing that if I stick to a 10% change maybe it won't hurt. I was also thinking about adding chlorine remover to tank first and then adding new water. Any opinions on that? thanks.