Penn Plax Aquarium Filter Bulk Activated Carbon 25lb

(25 lb, in a poly bag) Pro-Carb Laboratory-Quality Activated Carbon is fast acting, long lasting, and designed to keep your salt, or fresh water aquarium crystal clear for up to 4-6 weeks.Carbon removes harmful chemicals, toxins, odors, discolorations and other contaminants.Recommended for use in Cascade, and all other hang-on internal and canister filters.