Cloudy or white films on glassware after dishwasher cleaning are common problems that usually occur after the glass has been cleaned in the machine several times. Several possible reasons exist, some of which can be eradicated.
Hard Water and Soap
If the water used by the dishwasher is extraordinarily hard, it requires more detergent than usual to clean the glassware. Using more detergent removes the hard water minerals that accumulate on the glass and make it cloudy. Installing a water softening attachment at the water source is another option.
Dishwashers using water less than 60 degrees Celsius will turn out cloudy or filmy glassware. If the dishwasher has no internal heat booster, the hot water heater tank thermostat can be adjusted to appropriate levels.
Rinsing additives help prevent filmy glassware. They are available in the dishwasher detergent section of stores and enhance the sheeting action of the machine's water.
Glasses etched by cleaning agents in the dishwasher are irreparable. To determine if etching has occurred, soak the filmy glasses in full strength white vinegar for 15 minutes. If the cloudiness persists, the film is permanent. Dishwasher etching is not connected to the type or quality of the glass.