Try to put this to rest. My tap water has a ph of 8.4, city water. I have a 150. I have low ph fish. I have it at 6.8. If I put 2 gallons of city water in my tank it raises the ph .5. Anything more than this, in a 24 hour period, is nuclear for them. I buy all my water from Wal-mart, for now, moving in 3 weeks and will get an R/O system. I spent over $300 in chemicals trying to bring this ph down, when I started the tank, kill the hardness, etc. The best I got was 8.2. I put 2 goldfish in the tank and they died within 2 hours. I tried the same without the chenicals and the same results. They say we can drink the water but my fish can't live in it. That's why I'm moving. Get an R/O system if you're worried.