Dishwasher salt

In detail

Dishwasher salt is not a cleaning agent and it does not go anywhere near the load. Most dishwashers contain a built-in water softener — a bed of ion-exchange resin that swaps the calcium and magnesium in incoming hard water for sodium — and that resin becomes saturated and must be regenerated. The salt reservoir supplies a concentrated brine that strips the accumulated hardness ions off the resin and flushes them to drain, restoring its capacity. Three consequences are worth knowing. It is coarse and highly pure for a mechanical reason rather than a culinary one: table salt's anti-caking agents and fine grain can clog the softener unit, which is why the two are not interchangeable. Running the machine with an empty reservoir in a hard-water area means every cycle is run on untreated water, which is the fastest route to filming, spotting and — over many cycles — irreversible glass etching. And in a genuinely soft-water area the softener may be set to its lowest setting and consume very little, which is not a fault. The salt, the rinse aid and the detergent address three separate stages, and no all-in-one tablet removes the reason each exists.

Why

• Dishwasher salt is explained by Builders and water softening
• Dishwasher salt is explained by Water hardness