Aquacity Bio Sponge Filter Media Pad 35" Cut-to-fit Foam for Aquarium Fish Pond Reef Canister Tank Cut-To-Fit filter media Bio Sponge. Can be cut to fit your filters. Size: 35.4"x 11.8"x 0.79" Color: blue, green, or white. Good for both biological and mechanical filtration - offers more surface area for the beneficial nitrifying bacteria to colonize, eliminate toxic compounds and improve water quality ; trap large bits of waste, and will not get clogged easily.