Filler body - HX65K (1 m³)

In recirculation systems, the holding water is cleaned in an integrated water treatment process and then returned to the holding tanks. These systems are characterised by low water consumption. Recirculation systems consist of holding tanks, which are subsequently connected to mechanical filtration and biological water treatment, and possibly disinfection through UV irradiation or ozonation.

Water treatment is necessary to remove feed residues and metabolic waste products released by the fish from the system.

In the mechanical cleaning process, suspended solids are removed from the circuit.

The following biological cleaning stage provides a surface area for microorganisms that metabolise dissolved substances from the metabolism of the fish and the feed, thereby removing them from the water.

To provide the microorganisms with as large a surface area as possible, trickling filters or moving bed filters may be used in the biological stage.

HEL-X media have been optimised with regard to the requirements for use in biofilters. They provide a maximum surface area on which microorganisms can form a biofilm through colonisation. The media remain well permeable from all sides due to the circulating water, which ultimately has a positive effect on energy requirements. The surrounding helix gives the medium high mechanical stability, increases the surface area, and facilitates the colonisation by microorganisms in the flow shadow.