The IceCap 4-Stage Reverse Osmosis Deionization (RO/DI) system is designed to efficiently remove up to 99% of impurities from tap water, ensuring crystal clear and pure water for your aquarium. This robust filtration system features a single Dow Filmtec membrane in its durable clear filter canisters along with glycerin-filled pressure gauges for easy monitoring. It includes a sediment pre-filter, a carbon block filter, and a refillable DI cartridge with high-capacity resin that changes color to indicate when it needs replacement. The system requires no power source and can be installed quickly to start providing your aquarium with the best possible water quality.