My Dishwasher Leaves a White Film on the Glasses & Dishes. What Do I Do About It?

Hard Water

• The white film on your glasses, utensils and plastic items is calcium carbonate. It’s not dangerous, but it is unattractive and it’s a problem for people who have hard water. Hard water contains dissolved calcium and/or magnesium. These minerals are deposited on dishes at the end of the wash cycle, forming a film when they dry. Because hard water interferes with a soap’s ability to clean dishes, you need to adjust the amount of soap you use, depending on the hardness of your water. Use one tbsp. of detergent for slightly hard water; two tbsp. for moderately hard water; three tbsp. for hard water and four tbsp. for very hard water. If filling both soap cups doesn’t prevent filming, you may need to install a water softener.

Removal

• To remove the white film on your glasses and other dishes, add one cup of white vinegar to the cleaning cycle. The vinegar can be placed in a cup on the top rack. If spots remain, repeat with one cup of chlorine, followed by another cup of white vinegar to rinse. Alternatively, you can add citric acid crystals to the wash cycle. Metal flatware should be removed first as it can be damaged by this treatment.

Prevention

• Prevent spots and filming by adding a cup of white vinegar to the rinse cycle each time you use it. Rinse additives, which cause water to “sheet off” glasses rather than stick to them, can also be an effective way to prevent spots. Powder detergents are better than liquid detergents when it comes to preventing films, and tablets work even better. Another way to reduce white films is to use a dishwasher cleaner every six months.

Tips

• Soap dissolves better in hot water and rinses off your dishes more completely. The temperature of the water in your dishwasher should be 140 degrees Fahrenheit for optimal cleaning.

Phosphates

• Before new laws limited how much phosphorus could be added to dishwasher detergents, manufacturers would add up to 35 percent sodium tripolyphosphate to detergents, because phosphates are extremely effective when it comes to breaking down grease, softening water, and reducing or preventing spotting and filming. They’re also hard to remove in wastewater treatment plants, and when they’re released into lakes and rivers, they stimulate the growth of algae. The high levels of algae reduce the amount of oxygen in the water, which kills fish and plants. Environmental concerns are what led to the new phosphate limits.