Originally Posted by rrcoolj
Is your pH steady at 7.4? If your fish are tank raised I wouldn't worry about it. Tank raised fish are very durable and can cope with a variety of water conditions. A stable pH is better than the right pH. To know why your fish died we are going to need more information. Tank size, tankmates, filters, temperature, ammonia readings, nitrite readings, nitrate readings would all help.
pH would probably only change if tap water changed, but I don't measure often. Doubt DIY CO2 would do enough to drop it, and that hasn't been running lately. Tank is a 65g (36x12?x18?) w/Amazon Swords, Wisteria, some type of Hygro, and Chain Sword. Whisper 60 filter, 78-82F (was 78F at the time, bumped to 80 yesterday).
Tankmates are Bolivians, Germans, Angels, and Swordtails. Ammonia <.25ppm, Nitrite <.25ppm, Nitrate <5.0ppm... I'm starting to think maybe it got caught up in the Chain Sword and never made it out. It was a little tough getting it out of there.