I have learned not to over feed our fish. During one of the first weeks I really over fed our turtle and the water looked disgusting. He was decomposing a lot and added a lot of filth and nitrogen to the tank. One of the problems we had with the tank was trying to keep it clean and clear. It was always either a shade of green or very cloudy. I think something we did well was keeping a healthy living environment for our fish because none of them died due to our water.