High performance, non clogging, mechanical filter media for both freshwater and marine aquariums. Easy to remove & replace, fiber balls collect floating detritus & other toxic particles in water. Micron Size: 20-50um Density: 1.38/cm3 Filling Density: 60-80kg/m 3 Filtering Velocity: 20-85m/h Waste Stopping Quantity: 6kg/m3 Moisture Absorption: 0.4-0.5% Voidage: 96% Specific Area: 3000m2/m3 High Capacity Coarse Granular Ferric Oxide High Capacity Granular Ferric Oxide is 2 x more effective by volume than leading GFO. HC GFO controls and removes phosphates from water eliminating nuisance algae and green water. Diameter: 3-4mm Purity: 65% above Hardness: 4-5 Ash Mass %: 5 Premium ROX 0.8 Carbon Highest grade chemical filtration process that removes impurities such as copper, chlorine, medications, tap water impurities, discoloration and dissolved proteins. Iodine Number: 1000 min. Ball-Pan Hardness: 97 min. Surface area (BET) m2/g: 1225 pH: Neutral Food Chemicals Codex: Passes Ash, Mass %: 3 Methylene blue absorption g/100g: 24 Washed with Hydrochloric Acid