Due to the intensivemode of fish pr

Due to the intensive
mode of fish production in many of these systems, waste treatment within the recirculating loop as well as
in the effluents of these systems is of primary concern. In outdoor RAS, such treatment is often achieved
within the recirculating loop. In these systems, extractive organisms, such as phototrophic organisms
and detritivores, are cultured in relatively large treatment compartments whereby a considerable part
of the waste produced by the primary organisms is converted in biomass. In indoor systems, capture of
solid waste and conversion of ammonia to nitrate by nitrification are usually the main treatment steps
within the recirculating loop.