Maybe someone can help me here. I have a black moor that was upside down this morning when I woke I tested the water there is nitrites in the water I did a 30% change. He lives with a dojo and hillstream loaches in a 40 breeder that has been set up since November last year. If it was caused by the nitrites what do I do? They all eat repashy,duckweed,bug bites, cichlid excel, brine shrimp and blood worms sometimes. I do weekly water changes on this tank every Thursday. I have no idea what caused this! The only filter that I clean weekly is the intake sponge the rest get cleaned when I see a change in flow which is about every 2 months or so and I never do more than one in a water change. How can I help my fat Albert.