Separate water softeners of the ECO series, with electromechanical valve, transform ‘‘hard’‘ water into ‘‘softened’‘ water. The transformation occurs thanks to an exchange between sodium ions, fixed on particular resins, and calcium and magnesium ions in the water. This continuous exchange transforms normal water into softened water. When all sodium ions have been exchanged, the cycle is over. To give the resins a new efficiency, it is necessary to ‘‘recharge’‘ them with sodium chloride (table salt). This utterly automatic operation, called regeneration, consists of sliding brine through the resins. Drinking water treatment equipment per Ministerial Decree 25/12 and Ministerial Decree 174/04.