API Activated Filter Carbon is a unique, lightweight, coal-based carbon developed to work effectively in fresh or saltwater aquariums. This exceptional carbon removes organic waste, odors, colors, medications and toxins through chemical adsorption. Activated Filter Carbon is quick acting, promoting fish health by creating clearer, cleaner water. Can be used in any filter and will not elevate phosphate levels when used as directed. Can also be used in ornamental ponds. Shipping weight: 1 2/3 lbs.