Welcome to the Aquarium Filter Cartridges superstore! Keep the fish swimming strong with fresh aquarium filter cartridges for your tank. Whether freshwater or saltwater, Pet Mountain has you covered with a wide range of replacement water filter cartridges, Tetra filter replacement cartridges, Emperor 400 filter cartridge and other fish aquarium filter media equipment. Want your fish to stay healthy and happy? Treat them well with the very best products.