Recirculating Aquaculture Tank Production Systems A Review of Current Design Practice

tion method when temperature, salinity, disease, water supply, land availability, or exotic species /environmental regulations prevent more cost effective alternatives. A recirculating aquaculture system (RAS) can also be used to support traditional pond or net pen culture through broodstock or fingerling production. Recirculating systems have been widely used in research laboratories and universities across the country, but commercial use has been limited to relatively high value products. See SRAC Publication No. 456, A Spreadsheet Tool for the Economic Analysis of a Recirculation System for a discussion of the economics associated with recirculating aquaculture systems. The science and engineering of recirculating systems is well developed. The details of recirculating technologies have been exhaustively covered by Timmons and Ebeling (2007). This fact sheet summarizes the principal technological approaches being used in current commercial designs that may range in size from a few hundred gallons to nearly 100,000 gallons (1 to 400 m3). The technologies that support tank based culture must address five key issues; clarification, biofiltration, circulation, aerations, and degassing. Solids must be removed from the recirculating system through a clarification process. Dissolved organics and ammonia are then removed through a biofiltration process. The system must provide for circulation between the tank and filtration