The AquaFX Anion DI Resin CC Refill is a crucial component for achieving pristine, laboratory-grade water quality in your saltwater reef aquarium. This color-indicating deionization resin works in conjunction with your existing reverse osmosis system to remove the final traces of total dissolved solids, ensuring a contaminant-free environment for sensitive marine life and corals. This high-performance resin changes color from a vibrant blue to amber upon exhaustion, providing a clear visual cue for replacement. Manufactured in the USA, it boasts a hydroxide ionic form as shipped, a styrene/DVB gel polymer structure, and spherical beads for optimal flow. Key specifications include a total capacity greater than 1.0 meq/mL (OH Form) and water retention between 55 to 60 percent (OH Form), ensuring efficient and reliable contaminant removal. Ideal for dedicated reef aquarists, this AquaFX Anion DI resin is an essential part of a multi-stage RO/DI system, used effectively with Cation and mixed bed DI resins. It guarantees the complete removal of phosphates, silicates, nitrates, sulfates, and other impurities, allowing you to consistently achieve 0 TDS water. Using this resin helps eliminate potential water quality issues, fostering a healthier and more stable reef ecosystem for thriving corals and fish.