Aquapapa 4 lbs Activated Carbon Charcoal Pellets in 4 Mesh Bags for Aquarium Fish Tank Koi Reef Filters Removes odor, colors, organic pollutants to keep water crystal clear; removes toxic compounds from fish tank. Phosphate free. Safe for both fresh and saltwater tanks. Fast working and long lasting. Packages include: 4 lbs activated carbon in 4 zip mesh bags. 1 lb each bag. The zipper-designed mesh bag is reusable. ** Note: Always rinse carbon media thoroughly until the water runs clear before use. **