Combining our extreme activated carbon pellets with ammonia away green creates an incredibly effective system for removal of toxic substances, discolorations, odors and deadly ammonia. This special formulation features the two most essential elements necessary to maintain a healthy aquarium. Regular use of Acurel extreme blend in aquariums provides increased efficiency of filtration, and helps keep water odor free and prevents cloudiness. For use in all fresh and salt water aquariums. Available in 4 sizes for all your filtration needs.