Marineland Micron Cartridge for Magnum 200 Canister FiltersThe Marineland Micron Filter for Magnum 200 polishes the water by removing fine particles, leaving the water sparkling clean. The micron filter works efficiently for both freshwater and saltwater. Screens out both large and fine debris For use in the Magnum 200 Polishing Internal Canister Filter Great for fresh and saltwater aquariums Use overnight for increased water clarity Ideal for aquariums up to 60 gallons