Aqua Tech Power Filter Pump for 5-15 Gallon Aquariums AquaTech activated carbon removes odor, discoloration, impurities and toxins from water on contact. Activate carbon has thousands of tiny holes throughout its structure to capture varying sizes and types of molecules. Charcoal only has a few fissures on its surface and is not as effective. 1. Place Carbon In Media Container Or Mesh Bag. 2. Rinse With Tap Water to Remove Dust. 3. Place Media Container In Filter. 4. Replace Carbon Every 2-4 Weeks.Check out my other items!