Ammonia Poisoning
As the name suggests, this disease is caused when the amount of ammonia in the water increases. The level of ammonia should be zero as even a little increase in it can cause poisoning in fish. The symptom of ammonia poisoning is that the gills of the fish appear red or inflamed and they try to come out of the water for air. Ammonia poisoning can be treated by changing the water and using chemical neutralizer to reduce the level of ammonia.
