Dishwasher Salt Function
Some dishwashers have a water-softening feature that neutralizes the hard minerals naturally occurring in some water. Water with hard minerals is known as hard water, and these minerals leave built-up deposits that damage and corrode pipes and hardware, such as that of a dishwasher. Hard water also leaves behind spots or residue on dishes in your dishwasher. Adding salt to your dishwasher decreases the minerals in the water and keeps dishes cleaner and the appliance itself operating properly.
Appropriate Types of Salt
Table, rock, Kosher and sea salts, often used in cooking, are of no use to a dishwasher water softener because these kinds of salts may contain additives that damage the machine or actually increase water hardness. The salts may also clump or clog up the machine when they get wet. Granular dishwasher salt, available in appliance shops, is required for dishwashers as it has a fine consistency and is pure enough not to damage the machine.
Adding the Salt
Locate the water softener on your dishwasher. Often these water softeners have an indicator that lets you know when you need to add salt. Pour the granular dishwasher salt directly into the opening on the water softener until it is full and can take no more. If the water softener has no indicator light, set aside one day each month to regularly check the softener's salt and add more. A general rule is that one cup of dishwasher salt each month is enough to top off your water softener and keep it functioning properly.
Not every dishwasher has a water softener feature. However, if your dishes seem cloudy and you suspect hard water is the culprit, try a simple test. Place a cloudy glass into a pan of distilled white vinegar for five minutes. If the cloudiness clears up, hard water is the problem. You can create a homemade dishwasher detergent with added salt to clear your dishes up. Combine 1 cup each of washing soda (not baking soda) and borax with 1/2 cup each of citric acid and dishwasher salt. Shake to combine the ingredients, and use one tbsp. of homemade detergent per load of dishes.