The fully automatic water softener has been widely used in various steam boilers, hot water boilers, heat exchangers, steam condensers, air conditioners, direct combustion engines and other equipment and systems for circulating water supply. In addition, it is also used for domestic water treatment, as well as industrial water treatment in food, electroplating, pharmaceuticals, chemicals, printing and dyeing, textiles, electronics, and other industries, as well as pre-treatment in desalination systems. The hardness of the produced water can be significantly reduced after being treated with a single or multi-stage water softener.