It has 1 bag of 500g for easy change.High quality activated carbon made from coconut shell. Compared to traditional activated carbon, the number of micropores is greater, resulting in a greater surface area. One gram of COCONUT CARBON has a surface area of approximately 1100m2. This structure ensures excellent adsorbent properties, useful for cleaning water of the smallest molecules that affect color and smellRemoves yellowing of water caused by organicscompounds making the aquarium crystal clear and clean