I cleaned the fish tank today like I always have, but today the fish died. What did I do wrong?

Answer by  Fishyhead (6)

You could have cleaned your fish tank too well. Fish tanks develop helpful bacteria and algae for the fish. If you took all of that out of the water, you have caused "shock" to the fish. Also, the dramatic change in temperature can be harmful to the fish. Do partial cleanings or use bottom feeders to keep the tank regulated.

Answer by  justmesuzanne (625)

You may have forgotten to use dechlorinator or the temperature may have been too hot or cold or some foreign substance may have gotten into the water (e.g. soap, detergent, hand lotion?) It's hard to say. There are many things that can kill fish. I'm sorry for your loss!