Dish Washing

Filming and spotting are the most common aggravations that hard water can cause on dishes and glassware. Most dishwashing detergents contain water treatment chemicals such as phosphates to reduce this condition. The manufacturers of the detergents advise you that the harder the water the more soap you will need to use to get satisfactory results.

The amount of detergent should be increased according to the hardness (one teaspoon per grain). - Maytag Washing Machine Manual.