The AquaFX Whale Shark RO/DI System 200GPD is an advanced 7-stage water purification unit specifically designed for serious reef hobbyists. It produces ultra-pure, laboratory-grade 0 TDS water by meticulously removing harmful impurities like phosphates, ensuring the pristine water quality essential for sensitive reef aquariums. A standout feature is its AquaFX True 1:1 RO Membrane, which significantly reduces wastewater while maintaining high rejection properties. This system boasts three dedicated Deionization stages, including Cation, Anion, and Mix-Bed resins, allowing for comprehensive impurity capture and individual resin replacement. Pre-filtration is handled by a premium 1-micron sediment filter and two Chlorine Guzzler carbon block filters. Convenience features include an Auto Shut Off (ASO) kit, a manual flush kit, quick-disconnect fittings, and a Triple TDS Meter with a backlit display for precise monitoring. All components are mounted on a heavy-duty aluminum bracket, and the unit is proudly hand-built in the USA. The AquaFX Whale Shark RO/DI System is best suited for the advanced reef keeper who demands the absolute purest water for their aquatic environment. Its multi-stage filtration, particularly the three specialized DI stages, guarantees zero phosphates and other contaminants, creating an optimal foundation for coral health and growth. The innovative True 1:1 RO membrane also makes it an excellent choice for those seeking to minimize water waste without compromising purity.