Help promote crystal clear water and the growth of corals in saltwater aquariums and plants in freshwater aquariums with the ultimate filtration and convenience of API's Bio-Chem Zorb. Made with a unique blend of pharmaceutical-grade ion exchange resins， research-grade organic scavenger resins and high-porosity activated carbon， these ready-to-use filter pouches are designed to remove organic materials including colors， odors， heavy metals， toxic gases and compounds that carbon， alone， can't remove. It also eliminates light-blocking impurities to help stimulate coral and plant growth. This filtration pouch is ideal for aquarium start-up and regular maintenance.