Penn-Plax Ax3 Universal Cartridges | Fits All Ug Under Gravel Filters (2 Pack)

Ammonia-X – Ammonia Removing Under gravel Filter Cartridges is a quick easy disposable cartridge which acts as a lift insurance for your fish. Ammonia Removing Under gravel Filter Cartridges are made with top quality zeolites which work to eliminate the top fish killer ammonia. Under gravel Filter Cartridges solve the problem of overfeeding over-crowding and foul water conditions. Filter Cartridges fit all Under gravel filters.