AQUANEAT Aquarium Activated Carbon Filter Media Pad for Fish Tank Pond Canister Filter (10.5" x 36")Brand: AQUANEAT Color: Black Features: Activated carbon impregnated filter pad effectively traps large particles, removes discoloration, odor, pollutants, and harmful chemical to keep your aquarium crystal clear DIY Cut to fit filter pad, good to use in freshwater and saltwater aquariums Works with all filters: canister, hang on filter, wet dry, pond filters, DIY filters To ensure optimum performance, replace the filter pad every three to four weeks