How to Remove Hard Water Stains from Glass

The cloudy white film on shower doors and glassware is mineral left behind when hard water dries. Vinegar dissolves it. Use it on cool glass only, since hot glass can crack when it meets liquid.

Apply warm white vinegar

Warm 1 cup of white vinegar in the microwave for 30 seconds, until it is warm but not hot. Spray it on the glass or wipe it on with a cloth soaked in it. For a vertical surface like a shower door, press a vinegar-soaked paper towel against the glass so it stays wet.

Leave it for 10 to 15 minutes

Let the vinegar sit. Re-wet any areas that start to dry. The acid breaks down the mineral deposits so they come away without hard scrubbing.

Scrub with a non-scratch sponge

Scrub the glass in small circles with a non-scratch sponge. The film should come off as a gray haze on the sponge. Do not use steel wool or a scouring pad, which scratch glass permanently.

Treat stubborn spots with baking soda paste

For spots that remain, mix 3 tablespoons of baking soda with enough water to make a paste. Rub it onto the spot with the sponge and leave it for 10 minutes, then scrub again. The mild grit lifts what the vinegar loosened. For shower glass, half a lemon rubbed over the surface works the same way, since the citric acid attacks the minerals.

Rinse and dry with a microfiber cloth

Rinse the glass with clean water. Dry it right away with a microfiber cloth, buffing until it is clear. Leaving it to air dry lets new spots form.

Prevent it. Run a squeegee over shower glass after every shower. That alone stops most buildup. A rain-repellent windshield product applied to a clean, dry shower door makes water bead and run off for a few weeks at a time.

What not to do. Never mix vinegar with bleach, which releases chlorine gas. Do not pour vinegar on natural stone tile next to the glass, since acid etches marble and travertine.