Cutting without constraints of several sizes to improve the efficiency of filtration. It contains activated carbon to promote the retention of nitrifying bacteria, and thus improve the quality of the water and reduce the Fish mortality. Made of non-toxic three-hole foam with excellent water permeability. High porosity, open pores, air circulation, effective absorption, Repeated use after cleaning. Sealed under vacuum, dust waterproof, moisture, mold and easy to store, suitable for any type of aquarium. (After opening the package, leave it for 12 hours or wash the filter sponge with hot water, it will immediately find its original state). Size: 50x50x2cm-25ppi
