Chemi-pure Blue offers superior filtration for a variety of aquariums, featuring QuickWash Carbon™, a 0.8mm pelletized activated carbon with 30% more surface area. The hard, clean carbon reduces risk of HLLE in fish due to fine particles. It also includes two hybrid ion exchange resins for aquarium health. Benefits include reduced organics, odors, toxins, metals, phosphates, & silicates. It features low ash content, rinses quickly, & has prolonged life for less frequent water changes. It's scientifically designed to rapidly adsorb nitrogenous molecules, phosphates, & even nitrates. Directions: Rinse bag & put in sump, canister, or HOB filter; change every 2-4 months. CPBLU05-44 (5-44 oz) & CPBLUnano1-CD (0-5 Gallons) available.