Large amounts of particulate matter are produced during fish production. As a rule,one pound of fish waste is produced for every pound of fish produced. so suspended fish waster are a serious concern for RAS.Solids mainly result from fish waste and uneaten feed.The suspended solids can be a major source of poor water quality since they may contain up 70 percent of the nitrogen load in the system.As they not only irritate the fish's gills,cause several problems to the biological filter,and contribute a portion of the oxygen demand and toxic ammonia in RAS systems,but also promote the