Morton® Professional Water Softener Crystals are a non-food grade solar salt harvested from brine impounded in open shallow ponds that crystalized through slow evaporation by solar heat and wind. The harvested salt is washed to void inorganic impurities. The salt tends to crystallize in pyramidal aggregates which are broken up in milling to irregular rectangular particles and are crystalline to white in appearance. There are no additives in this salt. This product can be employed in any type of home or light commercial softener brine tank properly equipped to filter fine insoluble to avoid valve clogging. This product meets AWWA standard B200 for sodium chloride and is certified to NSF/ANSI/CAN 60 standards.