Phosphate Rx:Benefits: Phosphate Rx is an amazingly simple and effective product that has revolutionized the way phosphates are removed from saltwater and freshwater aquariums. Regular use of Phosphate Rx increases vitality, color and growth of your aquarium's inhabitants. Phosphate Rx is Veterinarian Approved, and has been used by leading Public Aquariums, Livestock Wholesalers, Retailers and Hobbyists. Directions:TEST YOUR AQUARIUM`S PHOSPHATE LEVEL PRIOR TO USE.