Aeration, water quality, and catfish production

Evaluation of catfish pond aeration systems has shown that daytime aeration by algae overshadows mechanical aeration and can reduce power requirements. The paddlewheel (modified oxidation ditch rotor) appears as the most reliable system. The power usage per lb. of fish is low enough to provide an economical production base. Paddlewheel tests have evolved a Level Raceway Concept which promises several advantages over the conventional earthen raceway. These include: a) lowering power requirements through lower lift requirements, b) eliminating field construction of water control drop structures, and c) continuing circulation after failure of one paddlewheel. Variations of the concept might include screening to separate the fish by sections and extending the number of pond units. Flow rates also could be diminished during daylight hours by reducing the number of operating paddlewheels. When the system could not be drained annually, a larger, unstocked pond connected in a series would improve water quality.