Ultra pure water is mainly used in the semi conductor and pharmaceutical industry. Because of the continuing miniaturilisation in the semi conductor industry, the specifications become more strict every year. Ultrapure water production often has to be done in two steps. For example, from tap water or fresh groundwater, the water should first be demineralised by membrane filtration or ion exchange to reach the ultimate conductivity of 10 uS/cm. The demineralised water is then processed through a high performance Mixed Bed or by Electrodeionisation to produce Ultrapure water.