【Wide application】 Our biochemical balls can be used not only in marine biochemical filtration systems, but also in freshwater biochemical filtration systems, perfect for use in aquarium, pond and fish tank. 【Function】 - A great helper to restore the natural water quality and provide the most suitable living environment for your fish. 【How to work】 - When the water circulates in the internal space, the time is extended, using the nitrifying bacteria to achieve the effect of biochemical filtration 【Large volume】 - Strengthen the bacteria filtering effect, lightweight and easy to carry.