Lees Under Gravel Zeolite Cartridges 2pk

An easy-to-install cartridge that solves the common problem of ammonia build-up that fouls aquarium water and destroys livestock. The Disposable Zeolite Cartridge is designed to fit Lee's Economy, Original or Premium Undergravel Filters. For optimal performance, it is recommended that you replace your cartridges every 2-3 weeks.