Vertical pump, pump sprayer, propeller-aspirator-pump, paddle wheel, and diffused-air aerators powered by electric motors or by takeoffs from farm tractors are used widely to aerate aquaculture ponds. Performance tests suggested that electric paddle wheel aerators are the most efficient in transferring oxygen and circulating pond water. A design for a highly efficient paddle wheel aerator is described. Aeration can improve dissolved oxygen concentrations, enhance the efficiency of feed utilization, and increase aquacultural production and profits. Aerator placement and the use of aerator controllers are discussed.