It is very possible that elimination of the "catfish" and or bullheads has resulted in dramatically less bottom feeding activity and sediment roiling. HOWEVER, the addition of chlorine (aka bleach or Chlorox) to natural waters which typically contain high amounts of various forms of organic particles (dissolved and suspended) will result in the production of high amounts of Trihalomethanes and similar volatile organic chemical contaminants such as bromodichloromethane, bromoform, chloroform, dibromochloromethane and haloacetic acids. These are fat soluable chemicals and are bioacumulative in the environment. They are typically stable and do not chemicially deteriorate and will pass from one organism to another up the food chain. BE careful how much fish you eat from this pond in the future. A search on Google will reveal more detailed information and the health hazards of trihalomethanes.
