As with land and crops, the fertility of the water determines the productivity of a pond. A typical pond supports 100 to 150 pounds of fish per acre. These organisms are fed upon by insects and small fish, which provide forage for larger game fish. Pond fertilization can, however, have negative side effects.
Excessive fertilization can create noxious algal blooms.
In addition, the decomposition of dead algae during summer months can cause low oxygen levels, which may cause fish kills during extended periods of cloudy weather. The aquatic food chain Fertilization is an advanced pond management option that definitely is not recommended for everyone. Ponds that are naturally fertile, have high flow rates, or don't get heavy fishing pressure should not be fertilized. Fertilization can increase productivity, but it takes time and money, and has to be done right to avoid problems. As a general guide, you can determine whether fertilization may be beneficial by the water clarity.