Pura (Magnavore) APU00404 Complete Aquarium Filter Media for 50-Gallon Tank, 8-Ounce Complete is a blended media that provides the most complete aquarium pollutant control at low cost Blended with 25-percent Phoslock, virgin bituminous acid washed carbon and caution exchangers Feature removes broad range of organics, heavy metals, toxins and aquarium scum promoters No additional specialty media are necessary to provide total, complete and cost effective aquarium waste management This 8-ounce Complete media comes with 6-inch by 12-inch 300-micron media bag; treats 50-gallon tank up to 6 months