The first time I saw the white crust on my shower door, I thought it was soap scum and attacked it with a scrub brush for half an hour. The stain laughed at me.

Hard water stains are minerals, mostly calcium, baked onto the glass. Scrubbing does almost nothing. Acid dissolves them, and you already have the acid in your kitchen.

Plain White Vinegar Does the Heavy Lifting

Fill a spray bottle with undiluted white vinegar and soak the glass. Let it sit for five minutes. You will see the white film start to soften. Then wipe with a damp cloth or sponge. The minerals lift right off.

For Thick, Stubborn Buildup

Soak a few paper towels in vinegar and press them against the glass for ten minutes. The towels hold the vinegar against the stain long enough to dissolve the thick stuff. This trick is how I got my door looking new again without any elbow grease.

The Squeegee Habit That Prevents It

After you fix the door, keep it fixed. Run a squeegee over the glass after every shower. It takes ten seconds and stops the minerals from drying onto the glass in the first place. I keep a cheap squeegee hanging in the shower and it has saved me hours of scrubbing.

What Not to Use

Avoid abrasive powders and steel wool on glass. They scratch the surface, and scratched glass collects even more scale. Stick with vinegar or a pH-neutral glass cleaner for daily upkeep.

Ten minutes of vinegar time, one squeegee habit, and my shower door has looked clear for months.