Penn Plax Pro-Carb Activated Carbon Crystals for Aquarium Medium 28-Ounce

(28oz) 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.