Features Combination chemical filter media removes organics, phosphate, and more Helps maintain a clean, clear, and healthy aquarium environment Ideal chemical filter media for reef and marine aquariums Premium chemical filter media blend of Seachem's Matrix Carbon and PhosGuard. SeaGel quickly removes organics, phosphate, silicates, toxic metals, and acids from saltwater aquariums. Unique bead-shaped filter media allows optimum water flow for efficient removal of aquarium impurities. Helps achieve a clean and healthy aquarium environment. A fine mesh bag is recommended. Great for reef and marine aquariums. Seachem SeaGel may also be used in freshwater aquariums that are not phosphate buffered. More Information Directions for Use: Use 250 ml/140 grams for each 40-60 gallons of aquarium water. Use in a fine mesh filter media bag. Rinse in fresh water before use. Replace after 3 to 4 months. May also be used in freshwater aquariums that are not phosphate buffered. NOTE: product will fizz and heat on initial wetting.