FISH TANK FOR INTENSIVE FISH FATTENING AND ARRANGEMENT FOR INTENSIVE FISH FATTENING

摘要

PCT No. PCT/EP87/00302 Sec. 371 Date Feb. 11, 1988 Sec. 102(e) Date Feb. 11, 1988 PCT Filed Jun. 10, 1987 PCT Pub. No. WO87/07475 PCT Pub. Date Dec. 17, 1987.Intensive fish fattening in open waters is increasingly disturbed by deposits of harmful substances. Fish fattening in artificial ponds is uneconomic because of the considerable outlay in terms of the fresh water and area required. These disadvantages can be overcome by a specially designed fish tank and a new process for operating such fish tanks. The fish tank (10) has, in its longitudinal center axis, a pit (11), into which a filler (31) with vertically extending flow channels (37) is placed. The fish water, together with an air/oxygen mixture, is circulated through these flow channels approximately 30 times per hour. The fish water is purified (nitrified) biologically according to the adhesive activated-sludge process by micro-organisms adhering to the filler. 50 to 500 liters of fresh water per kg of growing fish are added to the fish water, depending on the type of fish.