The Ideal H2O? Chemical Injection System includes a 30 Gallon Reservoir with a 4 GPD Peristaltic pump. The included peristaltic pump is self- priming and has an electronic timer module to accurately flow 4 gallons per day. This system is ideal for use with the Ideal H20? Antiscalant Chemical, drastically reducing the source water's hardness before entering your RO system.