Water quality is key for good health
Oscars and other fish have an immune system that fights off diseases. When the water quality is poor, the immune system is suppressed. This leads to illness. The chances of Hexamita problems is greatly reduced when you maintain healthy water conditions in the tank. No ammonia or nitrite and a pH that is above 6.0. This is especially important when you keep big fish that produce a lot of acid-producing wastes..
From James 41 days ago