100x13.5x3cm XY-1831 1) The bio Sponge filter able to be use in Marine, Fresh water and Planted tanks, which you are able to cut to the size you want which suits your filter. 2) The experts according to experiment concluded that the molecules hole size and softness is best suitable to develop the best for bacteria. 3) The bio sponge is able to dissolve waste of fishes and also improve water quality than will reduce death rate of fishes in tank. 4) Monthly once washing of bio sponge filter by using running tap water to clean, after washing and cleaning its shape will remain, the hole will not be blocked by dirty particulars, it can be reused continuously.