【Porous Function】 Multi-porous feature will avoid blockages and provide the largest adhesion area for bacteria, so as to cultivate high density nitrifying bacteria. 【Can Be Use】 This fish tank biochemical filter sponge can be used in sea water tank and fresh water tank. It has the best effect on decomposing the excrement and the forage leftover. Strong filterability, can stable water quality and reduce fish died. 【Easy To Use】Thickening biochemical filter sponge, tough and The size can be cut freely as you need.Can be cut any sizes as your needed, and can be used repeatedly after cleaning, extremely convenient.Package Included: 1 x Filter Biochemical Sponge Pad 【Features】Strong filterability, can stable water quality and reduce fish died.Thickening biochemical filter sponge, tough and durable.Good shading features, can reduce the algae breeding. 【Repeatable Use】Has the best effect on decomposing the excrement and the forage leftover, can be used in sea water tank, fresh water tank and aqua-plant tank.Can be used repeatedly after cleaning.