Softening the water
The place where you put the salt in - big screw on lid - to remove ions from the water...
Softening hard water
The damaging effect that hard water can have means that it may be beneficial to soften the water. Methods for softening hard water involve the removal of calcium ions and magnesium ions from the water.
Dishwasher salt is a particular grade of granulated, crystalline sodium chloride intended for use in dishwashers. Like water softener salt, dishwasher salt regenerates ion exchange resins, and removes the calcium and magnesium ions that characterize hard water. Dishwater salt granules are larger than those of table salt. The granule size ensures that the salt dissolves slowly, and that fine particles do not block the softener unit.
Good Luck..., January 2017