The resin attracts the temporary hardness salts – calcium carbonate and magnesium carbonate – which we normally identify as scale, as well as heavy metals. Although this is a water softening process it should not be confused with general water softeners (which are sodium based and inappropriate for use with potable water applications) and they are classed as dealkalisers (dealk). Whereas water softeners can be regenerated at point of use using salt, a dealk unit cannot be regenerated at point of use and has to be exchanged.
Like conventional water softeners the dealk resin is housed in a tank with inlet and outlet water connections. Most dealk units are available in different sizes and frequency of change depends upon water hardness and volume of water used. The hardness level measured is the temporary hardness and not total hardness.