Hi, the pH has crept up to 8.3 in my established 75 gallon, heavily planted aquarium. The plants continue to grow well and the fish seem fine. Should I worry? Fish are mostly about 2-years: 3 angels, a geophagus, tiger barb, red tail shark, betta, blue gourami, 3 plecos, 9 cardinals. A couple months ago I lost the male angel to an infection -- tried to treat him but he didn't make it, although I did save the female who also got sick -- and have been doing 50% water changes every week since then. Tap water is high, around 8, and pretty hard, according to a fish store guy. I've been told I could try reducing the water changes to every 2-3 weeks, just monitor the nitrates (10ish now) and make sure they don't creep up beyond 20-30. I also know about peat moss, and have some on hand. I'd definitely rather not add chemical pH reducers. Any advice would be appreciated.