Phosphate Remover Quickly removes phosphate Improves turbidity ML/PR is harmless to invertebrates, and has been tested with and shown to be safe with most species of marine fish. Fish of the Acanthuridae family (Tangs, Surgeonfish) have shown a sensitivity to this product. We DO NOT recommend the use of ML/PR where these fish are present. Due to that fact that the chemical properties of the water in every aquarium are unique as a result of varying source water quality, the live and inert components introduced into the aquarium, and the chemical treatments used, it is impossible to predict how the product will react in every aquarium environment.