What is the white residue in dishwashers?

The white residue in dishwashers is a deposit of hard water and minerals. Environmental regulations required dishwasher detergent manufacturers to remove phosphates, which cause algal blooms in lakes, from their detergents. The lack of phosphates allows hard water deposits to accumulate.

To prevent white film from building up on the dishwasher and dishes, use a fruit acid or citrus oil additive made specifically for dishwashers. To remove existing buildup, empty the dishwasher of dishes, and use either a commercial dishwasher cleaner or 1 pint of white vinegar poured in the rinsing basin. Rinse aids remove excess water before it evaporates and leaves residue.