Over time, drinking glasses can develop a cloudy, hazy appearance from deposits left by hard water. Fortunately, you don't have to get rid of your old glasses and buy new ones if these stains appear. You can remove hard water stains from drinking glasses using natural, inexpensive products you probably already have in your own home.
Soak the glasses in a sink full of white vinegar. Allow the glasses to soak for about 20 minutes.
Remove the glasses from the sink.
Pour some baking soda into a bowl.
Wet an old toothbrush and dip it into the baking soda to load the brush.
Scrub any remaining hard water stains with the baking soda.
Rinse the glasses clean and dry them gently with a lint-free cloth.
Prevent future hard water stains by washing the glasses by hand with a gentle liquid dish soap and drying immediately. You can add powders or liquids to dishwashers to prevent hard water build-up.