Cloudy stains on your glassware can be washed away by hand, but often are difficult to remove. The stains are calcium deposits and can be caused by hard water or by using too much dishwasher detergent. Old and new glass are just as susceptible to the stains, and if they are left in place too long the stains can become permanent. If you take care of the stains right away, you can remove them with little elbow grease.
Mix equal parts of white vinegar and water in a large pan or stock pot. If your glassware is extremely cloudy, use undiluted white vinegar.
Heat the vinegar and water solution until it is warm. You do not need to boil the mixture. Remove the pan from the burner.
Place your stained glasses in the vinegar and water. The solution must completely cover the glasses. Add more vinegar and water, if necessary.
Soak the glasses in the warm vinegar and water for up to 30 minutes.
Remove the glasses from the vinegar and water. Wash them with a mild soap and warm water. If they are still cloudy, wipe with undiluted vinegar and a soft towel and wash again with mild soap.
Dry the glassware by hand after the final wash to avoid water spots.
Try using undiluted white vinegar in your dishwasher's rinse aid dispenser if you have consistent trouble with cloudy glassware. You can also try using slightly less dishwasher detergent to see if that corrects the problem. If you have hard water, consider installing a water softener. You can contact your water company to ask whether you have hard water in your area if you are not certain.