Penn-Plax offers a method to purchasing Activated Carbon in bulk to all Aquarium hobbyists, beginners, and general customers. Each bag contains 25 lbs. of Activated Carbon, making for a value pack. The Carbon pellets are approximately 0.25” long. You save more money on aquarium filter media when bought in bulk! Scientifically Formulated: Our laboratory quality Activated Carbon is fast acting and long lasting. Furthermore, they’re designed to keep your aquarium crystal clear for 4 – 6 weeks, and are safe for freshwater and saltwater tank setups. Clean & Healthy: Our Activated Carbon removes harmful chemicals and toxins, clears up discolorations, and reduces foul odors from your aquarium’s water. Helpful Tip: If you look through the side of your tank, and cannot easily see the other side, you probably need to add some Activated Carbon to clear up the water. Thoroughly rinse the Activated Carbon before use.