This 30k water softener two tank unit, model PWSR30K, is designed for residential and light industrial use applications. This unit uses components that are NSF 61 listed. The state-of-the-art computer programming increases efficiency and saves salt and water. The PWSR control valve is manufactured from high-tech materials and has been engineered and tested to perform in the most demanding environments. It has built a reputation of being one of the most reliable valve platforms in the industry. The exchange media is a high capacity cations polystyrene resin that combines high operating capacity with excellent chemical and physical stability for long dependable life. The resin tank features a non-corrosive fiberglass tank with a thermoplastic inner liner. The brine tank is a combination brine maker and salt storage vessel and is made of tough, corrosion free, high-density polyethylene. All surfaces contacted by water are made from 100% polymer components so that corrosion from acidic water.