Abstract: The present invention provides a method for the removal of noxious taste or odor compounds (TOCs) from water of an aquaculture system, the method comprising contacting the water with a carrier comprising: a hydrophobic agent being configured to adsorb said TOCs; and a hydrocolloid, wherein the carrier is adapted for the colonization of microorganisms which are capable of degrading said TOCs. Further provided is a recirculating aquaculture system (RAS) for maintaining aquaculture species, comprising, inter alia, a reactor comprising a plurality of carriers comprising a hydrophobic agent configured to adsorb TOCs, and a hydrocolloid.

Abstract: A system for nitrate removal from aquariums, both fresh water and marine aquariums, by means of permeable polymeric beads which contain a combination of fermentative and denitrifying bacteria and a carbon source. Preferred beads are beads made from sodium alginate or chitosan. The bacteria, in the presence of the carbon source, are able to reduce nitrate to nitrogen gas. Bacteria which are not harmful to fish are used. The porous beads used in the process are novel and part of the invention.

Abstract: There is provided a system for water quality control and improvement in intensive fish culture systems. The aim of the water treatment is to reduce the content of inorganic nitrogen and of organic matter. The system comprises a fish pond, a settling pond, a fluidized bed reactor and a trickling filter. The system according to the invention can be an essentially closed one, except for periodic water replenishment. It is suited for ponds with sweet or salt water.