Kolar Filtration GFO - 1 Pound Bag of Phosphate Removal Media for Salt Water Reef Aquariums and Coral Health HIGH QUALITY: High quality ultra-pure virgin GFO with reduced fines. Removes phosphate in water REDUCES ALGAE: Kills algae and prevents them from coming back by removing their food source, phosphate RINSE BEFORE USE: Give quick rinse to remove any dust from shipping SAFE FOR ALL AQUARIUMS: Works in salt water & freshwater aquariums, ponds, and more MADE IN USA: Family owned and operated; produced entirely in the USA