Aquarium Pond Coarse Filter Sponge up to 20" L x 20" W x 1.18" Thick approx. Bulk Cut & Fit Aquarium Fish Tank Wet Dry and Pond This high quality coarse filter sponge is designed for water filtration in fresh/salt aquarium and ponds. It effectively removes particulate matter mechanically. It also adds a supplemental means for removal of ammonia by providing more surface area for growth of beneficial bacteria. Buy in bulk and cut your own size filter pads to use on a variety of water filtration applications. This coarse sponge is specifically manufactured for aquarium and pond use. The larger inner surface area is ideal for beneficial biological bacteria to colonize. The reticulated structural design also provides better water flow and has less chance to clog. DIMENSION:20" long x 20" wide x 1.18" thick (50 x 50 x 3 cm) approx. Specification: Coarse Black Filter Sponge