When I was 9, I had a 5G tank with black mollies. I was fascinated with livebearers.
I don't know how the fish survived! I would periodically clean the tank by removing the fish, scrubbing the tank, gravel, etc. with soap, removing the filter floss and charcoal from the box filter, replacing the water with chlorinated tap water, then adding fish. Needless to say the fish were stressed by the end of their ordeal.
Thankfully, I have improved my fish keeping techniques since then.
I don't know how the fish survived! I would periodically clean the tank by removing the fish, scrubbing the tank, gravel, etc. with soap, removing the filter floss and charcoal from the box filter, replacing the water with chlorinated tap water, then adding fish. Needless to say the fish were stressed by the end of their ordeal.
Thankfully, I have improved my fish keeping techniques since then.

