Salt suitable for regenerating residential and commercial cation exchange water softeners. Most commonly used for this purpose is sodium chloride (NaCl) in crystal or pelletized form. Rock grade salt should be 96-99 percent NaCl; evaporated salt should be 99+ percent NaCl. Potassium chloride (KCl) may also be used for the regeneration cycle in the cation exchange process, thus minimizing the amount of sodium added to both the softened water and the spent regenerant water going to the drain.