This was before I learned about water changes and cycling( 1 y r ago haha) When the water in the tank wouldnt look clear I would pour some bleach into the tank until It was clear again. I did this like 2 times a week. When I would clean the filter out spic and span I would soak the pads in bleach water until they were white again. None of my fish died or anything. Its been little over a year now of doing it properly and they just keep getting bigger