【Good Filtering Effect】Mechanical grinding high temperature calcination ceramic ring, dense microporous structure, can effectively absorb harmful chemicals, micro particles and debris in water and remove odor. Resolve impurities,Stabilize PH,Clarify your water naturally provides a good breeding ground for nitrifying bacteria, quickly decompose harmful bacteria, purify water quality, and cultivate beneficial bacteria with these bio-balls. 【Note】Please clean the filter material before using. 【Quality Guarantee】Guarantee refund, if you have any dissatisfaction on the quality of goods, please contact us, we are willing to send you a new goods or a full refund. 【Wide Application】With fine net bag, wide range of application. Used for upper filtration, bottom filtration and outer filtration of fish tank. The filter material can be used on both seawater and fresh water. Small size, mostly used for wall mounted filter. 【Strong Adsorption】With strong adsorption characteristics, adsorb harmful substances, culture nitrifying bacteria, stabilize water quality in the tank.