The floating in-pond raceway (IPR) i s a channel that floats in a pond with a device that pushes water through system. It has potential to improve presentation of feed to the fish, assure good oxygen concentrations for growth, improve feed efficiency, improve inventory control, minimize predation, facilitate management of disease, and increase access for harvest . Utilization of a grid style airlift (GAL) is a significant improvement in the technology that has resulted in rapid adoption overseas in systems where the IPRS is constructed as a fixed structure in a pond designed for both intensive aquaculture production and waste management.
A modest size floating raceway has been developed by investigators at KYSU based on suspension fr om a floating frame and equipped with a grid style airlift to induce flow at about 20 exchanges/minute through the system. This design is something that can be constructed on the farm with material costs for the raceway, floatation, air blower, screens, and airlift estimated to be about $2,500. Though the entire unit is 32 feet long, the volume containing fish is about 9 m3 (21x4x4 ft) and is capable of supporting 460 kg at a loading rate of 48 kg/m3 (3 lb/ft3). Floatation and double keyways are built into each unit. These raceways feature a uniform square cross section and hard flat bottom such that a worker in waders can crowd, grade, and/or harvest the fish.
Initial evaluation of these raceways have been with phase I and phase II largemouth bass.