Is it possible that a high ph can kill fish. My ph is running at 7.6 (or maybe even higher). I bought 5 tiger barbs and 2 died. I then bought 3 more and 2 more died. The remaining 4 look very healthy and happy. All others appeared to be in good health but were dead by next morning. My tank is cycling but it has not yet registered any ammonia, nitrites, or nitrates...Alll readings are zero. This tank has been cycling for about 5 weeks so I would have thought it would have started by now..Would a water change help any of these issues..And if ph is too high, how do you lower it....Everything I have read on this seems to indicate not to add any ph chemicals to water..Any suggestions would be greatly appreciated.