Aquaculture or Aquafarming is the farming of aquatic organisms such as fish, crustaceas, molluscs and aquatic plants under controlled conditions.
Aquafarming can take place in simple garden ponds, on hatches in a Scandinavian fjord or in a highly engineered tank circulation system.
Due to overexploitation of marine species, the demand for aquaculture products is growing constantly.
In a recirculating aquaculture system (RAS) the water purification system must be integrated. Waste water is cleaned undergoing various stages of treatment and finally led back into the aquatic tank or vessel.
After leaving the fish tank the water is treated for solids before entering a biofilter here biocarriers are applied.
During the biological treatment process ammonia is converted into nitrate, afterwards the water is denitrificated. The water then is degassed, oxygenated and sterilized and eventually recirculated.
To offer a maximum face for a natural, biological biofilm-growth can be applied in floating or trickling filters (clusters). The media has been optimized for the use as biofilter. provide high flow-rate. The circumferential helix with inward-looking lamellae allows irrotational flow and increases the amount of shielded surface which facilitates microorganisms to grow even in shadowed flow-zones.
The choice of adequate material can reduce costs and helps to increase the effectiveness of a system considerably.