Water stains on the glass are often the result of hard water, which contains minerals and sediments that leave a hard limestone stain on the glass. This will be most noticeable on glass shower doors, hand-washed glasses, even the exterior windows of your house, if you use the pressure hose wash them.
Preparation for water staining
If you are cleaning shower doors, drinking glasses or some other relatively small area of glass, pour or distilled water on the spots to wet down the sponge. Rub an old towel over the point to loosen mineral deposits, if possible.
Try natural cleaners
Make a wash of vinegar paste and baking soda, apply to the stain and leave for a few minutes and then scrub the bubble with a sponge. You can drink glasses of hot white vinegar until the spots dissolve, then wash and dry.
Persistent glass stains can be removed with ammonia if vinegar does not do the job.
Wipe exterior windows by rubbing a dry newspaper over the stain, then wet the newspaper and rub again. Rinse with distilled water and air dry.
Carry out the great weapons
Use glass magic, lime or CLR persistent water spots. All are commercially available products that are sold in grocery store, hardware and home improvement stores. Non-toxic products are designed to dissolve mineral deposits to make it easier to remove stains, but it’s worth trying simple solutions like vinegar first to save money.