To reduce phosphorus concentrations in recirculation aquaculture systems (RAS) have mainly dealt with improving the bioavailability of phosphorus in fish feed. In the present study,. results are presented on a prototype recirculating treatment system submerged biofilter designed for removal of organic mailer and inorganic nitrogen, organnic photphorus. To determine the effect of salinity on the phosphorus remove rate (PR) in laboratory scale (inverse correlation petween salinity and phosphorus remove rate has been determined.) Determination of phosphorus remove rate in the treatment system submerged biojilter scale and Pilot-scale production applications. BOD5/PO4 coefficient determined. Results showed that, in laboratory scale process to accumulate phosphorus with ratio BOD5/PO4 10. Pilot scale production and application of the coefficient of BOD5/PO4 6. After operating time, will accumulate phosphorus exceeds a certain level, and instead of new water production.