Brightwell Aquatics Purit is a next-generation combination of enhanced activated carbon and NSF-grade ion-exchange and adsorptive resins to enhance removal of impurities such as chloramines, ammonia, nitrate, phosphate, silicate, heavy metals, and dissolved organic material from water. This enhanced filter media offers superior chemical filtration characteristics when compared to traditional activated carbon. Purit facilitates decomposition and enhances oxidation-reduction potential (ORP). This filter media also improves water clarity and water quality by removing dyes and discoloration, eliminating odors related to decaying organic material, and removing copper, lead, and other heavy metals from your tank. Completely safe for use in all reef, mixed-reef, fish-only, community, and planted aquaria.