LiquaGen 5-Stage Reverse Osmosis/Deionization (RO/DI) - Aquarium Reef Water Filter System, 50 GPD This product is great for aquariums, laboratory testing, and other applications where ultra-pure water is necessary. Pre- Assembled system for easy installation. Guaranteed 0 ppm water. No more running to your local fish store! High Rejection Reverse Osmosis (RO) Membrane Capacity : 50 Gallons Per Day (GPD). Film by GE USA 1 year manufacturer warranty; Lifetime customer support. Designed for city water use, incoming TDS should not exceed 350 TDS. NOTE: Auto shut off valve and check valve will only be included upon customer request (only needed if you plan to connect the system to a storage tank). Designed specially for customers who are buying an RO/DI for the first time. Extremely simply and easy to use!