Tetra Easy Crystal Filter Pack 250 / 300 No Carbon

Tetra Easy Crystal Filter Pack 250 / 300 (without carbon) is a replacement filter cartridge suitable for the Tetra Easy Crystal Filter Box 250 and Tetra Easy Crystal Filter Box 300 (also sold in Tetra Aqua Art and Tetra Starter Line aquariums). For crystal clear, healthy water, replace every 4 weeks. Contains 3 filter cartridges.