King British 6 in 1 Water Test Strips Aquarium and Pond, sgl

King British Filter Aid+ is a rich-source of friendly-microbes that will help you maintain better water quality. A weekly addition to your aquarium water will reduce harmful ammonia & nitrite, making the water safer for your fish. Regular use improves the development of the biological filter for clean, clear water. For use in coldwater, tropical and marine aquariums. One 50ml bottle will enrich up to 450 litres.