Tom Activated Carbon Pillow with Cloth Carbon for Rapids Pro Series PS3 & PS4 

Pros Series Cloth Carbon is cleaner and purer than other traditional forms of acitvated carbon but still retains 100% activation which gives it the same high capacity for adsorption of organic compounds and other odorous gases. Pro Series Cloth Carbon works by attracting and holding certain harmful chemicals as the aquarium water passes through it. Since Cloth Carbon is a highly porous material, it has an extremely high surface area for contaminant adsorption. Most effective in removing organic contaminants from the water. Faster adsorption kinetics.