FISH BASIN FOR INTENSIVE FISH-FATTENING AND PROCESS FOR OPERATING SUCH A FISH BASIN

摘要

The intensive fattening of fish in open waters is increasingly pertubed by pollutant deposits. Fish fattening in artificial pools is uneconomical because of the high consumption of freshwater and the surface area required. These disadvantages can be avoided by a specially-designed fish basin and a new process for using such a basin. The fish basin (10) is provided, along its longitudinal centre-line, with a trough (11) in which is placed a bed structure (31) with perpendicularly extending flow ducts (37). About thirty times an hour the fish water is circulated via these flow ducts, with an air/oxygen mixture. Microorganisms which adhere to the bed structure biologically clean (nitrify) the fish water by means of the adhesive activated sludge process. Depending on the type of fish, 50 to 500 litres of freswater is added to the fish water per kg of fish growth.