Penn-Plax Cascade Pro-Carb Filt-A-Pack, 2 Pack - Carbon Aquarium Canister Filter Media Bags - Pre-Bagged Nylon Mesh Replacement for Cascade Systems, Freshwater & Saltwater Tanks - 8 Ounce

The Penn Plax Pro Carb Nylon Mesh Filter Bags for Cascade Canister Filters are filled with Pro-Carb laboratory quality activated carbon to ensure your aquarium water is clean and clear.  Every pack comes with two, 8 ounce bags.  This filter bag will remove chloramines, chlorine, tannins (which color the water) and phenols (odor causing chemicals) and many more.  You will see the difference in water quality almost immediately.  The bag measures 8x4 inches and is designed to fit into the filter tray without any gaps.  You will never have to worry about the water getting through the gaps and not being filtered.  Before installing the filter bag, rinse the carbon filter thoroughly under cold water.  This will help remove any loose carbon particles.  Also fits the following filters:  Eheim ECCO, Eheim Pro/Pro II, AquaClear 500 and FilStar Canisters.