Red Sea NO3:PO4-X Nitrate and Phosphate Reducer Biological Nitrate And Phosphate Remover Prevents Nuisance Algae And Enables Control Of Zooanthealle For Optimum Coral Growth And Coloration Promotes The Biological Reduction Processes Of Nitrate And Phosphate By Bacteria To Reduce Nuisance Algae It is part of the reef care program and is an essential pre-requirement for using the reef colors supplement family that enables corals No3:Po4-X Must Be Accurately Dosed By Using Nitrate And Phosphate Pro Test Kits And Cannot Be Used With Other Phosphate Removers Available In 500-Ml Bottle