Preventing & Removing Cloudy Glassware Stains The color change to blue, purple, pink or brown is an indication that etching has begun. This is a permanent film that occurs in unusual circumstances and causes glassware to pit or erode. In advanced stages, the glasses will appear frosted, spotted or cloudy. To Identify To verify that the film is etching, soak the glass approximately 5 minutes in undiluted white vinegar. Rinse and dry. If the film is not removed, it is etching. If the film is removed, it is possibly hard water filming. (See Dishwasher - Hard Water Filming) Causes Certain types of glassware will etch in any dishwasher with the combination of: Soft water (0-3 grains per gallon) Excessive detergent Excessive water temperature Pre-rinsing of items There is no way to predict what glassware may be affected by etching as there is no relationship to the cost or quality of the glass. To Prevent Since etching usually happens in soft water (0-3 grains), adjust the amount of detergent to match the hardness of the water. Your local water utility or a water quality company such as Culligan or Kinetico can tell you the water hardness for your area. As a general rule, one teaspoon of detergent is needed per grain of water hardness with a minimum of three teaspoons. However, when using a concentrated dishwashing detergent, decrease this amount by half. For a normal cycle place the recommended amount of detergent in each detergent cup. For shorter cycles place the recommended amount of detergent in the MAIN WASH cup only. Lower the water temperature so that it enters the dishwasher at approximately 130-140 degrees F. Check the water temperature by placing a food thermometer in a glass and letting it fill with water from the hot water faucet. Let the water run until the temperature stops rising. If it is over 140 degrees F., lower the water heater setting. Use water heating options on your dishwasher when incoming hot water is 120 degrees F. or lower. Do not manually prerinse dishes before loading in the dishwasher. This will aggravate etching. To Remove There is no way to remove the filmy appearance caused by etching - the damage is permanent. However, by following the previous recommendations, future damage may be prevented.