API Bio-Chem Zorb Pouch, Size 6Containing a superior blend of resins and activated carbon that removes aquarium pollutants including colors, odors, heavy metals, and toxic gases API BIO CHEM ZORB filtration media makes aquarium water crystal clear. Product also removes light blocking impurities for improved growth of corals in saltwater, and for plants in freshwater aquariums. 1 pack size 6. Rinse pouch under tap water to remove the loose dust. Pouch does not need to rinse clear.