PETCO Power Filter Replacement Cartridge 20 B - Purple

PETCO Replacement Power Filter Cartridges 20 B - Purple are compatible with the PETCO Power Filter 20 - Purple and the Penn Plax Cascade 100. These can be installed quickly and are recommended for 5-20 gallon tanks. Each cartridge contains 1.2 ounces of research grade activated carbon.PETCO Replacement Power Filter Cartridges 30 C - Green are compatible with the PETCO Power Filter 30 - Green and the Penn Plax Cascade 150 & 200. These can be installed quickly and are recommended for 10-30 gallon tanks. Each cartridge contains 1.5 ounces of research grade activated carbon.PETCO Replacement Power Filter Cartridges 65 D - Orange are compatible with the PETCO Power Filter 65 - Orange and the Penn Plax Cascade 300. These can be installed quickly and are recommended for 20-65 gallon tanks. Each cartridge contains 4.5 ounces of research grade activated carbon.Each type of replacement cartridge is available in packs of 1, 3, or 9.