Why won't soap scum come off my shower glass?Updated 6 hours ago
TL;DR: If your shower glass still looks cloudy after cleaning, it might not be soap scum at all. Mineral buildup or glass etching can look very similar but they behave differently. Soap scum responds to Bathroom & Shower Cleaner, dwell time, and light agitation. Mineral buildup needs more work (or a specialist descaler). Etching is permanent surface damage that no cleaner will fix. Use the checks below to figure out what you're dealing with.
Last reviewed: April 2026
What's actually on my shower glass?
Three things look similar but are very different problems. Soap scum is a film of soap, body oils, and grime sitting on top of the glass. It's removable with the right cleaner and some patience. Mineral buildup is calcium and magnesium from hard water that's dried onto the glass. It feels hard or gritty under your fingertips and needs more aggressive treatment. Glass etching is permanent microscopic damage to the glass itself (usually caused by long-term mineral exposure, acidic cleaners, or abrasion). It feels smooth but looks hazy, and no cleaner will fix it.
✓ Soap scum
Film from soap and body oils. Feels slightly slick or waxy. Responds to the right cleaner, dwell time, and gentle agitation.
⚠ Mineral buildup
Calcium and magnesium from hard water. Feels hard or gritty. Needs repeat cleans or a specialist descaler to shift.
⚠ Glass etching
Permanent damage to the glass surface. Feels smooth but looks hazy. No cleaner will fix it, the glass needs replacing or resurfacing.
How do I tell which one it is?
Run your fingertips across the cloudy area when the glass is dry. Slick or waxy texture suggests soap scum. Hard or gritty texture suggests mineral buildup. Smooth but still hazy suggests etching. Second check: clean a small patch thoroughly with Bathroom & Shower Cleaner, then rinse and dry. Compare it to the surrounding area in good daylight. If the cleaned patch looks noticeably clearer, it's soap scum or mineral buildup. If the cleaned patch looks identical to the cloudy surrounds, it's etching.
✓ Two quick checks
Fingertip test. Dry glass, run your fingertips across. Slick = soap scum. Gritty = mineral buildup. Smooth but hazy = etching.
Clean-patch test. Thoroughly clean a small area. Compare to surrounds in good daylight. No visible improvement means etching.
How do I fix soap scum?
Spray Bathroom & Shower Cleaner, let the foam sit for 5 to 10 minutes (not the usual 2 to 3), wipe with Ultra Pro Bathroom Mitt, rinse thoroughly with water, dry with a clean cloth. Repeat if needed, heavy soap scum can need two or three applications to fully shift. For really stubborn spots, step up to Diamond Sponge with light pressure (glass is tough but a Diamond Sponge still requires care).
✓ Soap scum fix
Spray and extend the dwell. 5 to 10 minutes, not the usual 2 to 3. Give the formula time to break the film.
Agitate with Ultra Pro Bathroom Mitt. Firm circular motion. Step up to Diamond Sponge for stubborn spots.
Rinse and dry fully. Water rinse, dry with a clean microfibre. Dry glass is clear glass. Repeat the whole cycle if needed.
What about mineral buildup?
Mineral buildup (calcium, magnesium, limescale) is calcium-based. Alkaline cleaners like Bathroom & Shower Cleaner don't dissolve it effectively because minerals need an acidic cleaner to break down. For hard-water deposits, you need a dedicated descaler (like vinegar-based products or a commercial limescale remover). Use it sparingly, rinse thoroughly, and never combine with Bathroom & Shower Cleaner (mixing cleaners can deactivate both). Once the mineral layer is gone, switch back to regular cleaning to prevent recurrence.
What if it's etching?
No cleaner will fix glass etching because the damage is to the glass surface itself, not a layer on top. Options are limited: professional glass polishing (an acid-based restoration service, not cheap but sometimes effective on light etching), replacing the glass panel, or applying a protective coating like EnduroShield to new glass to prevent future etching. Prevention for future glass: squeegee after every shower with Bathroom Squeegee. Dry seals and ledges. Never let hard water dry on glass.
⚠ Etching isn't cleanable
The damage is to the glass, not a layer on top. Options: professional glass polishing (sometimes effective on light etching), replace the panel, or protect new glass with a coating like EnduroShield. Prevention for future glass: squeegee after every shower.
Still not happy with the result?
If you've worked through the checks and the cleaner isn't delivering what you expected, reach out to our team. We'll help troubleshoot the specific situation and, if needed, back it with our 30-day money-back guarantee. Send a photo of the glass and a quick description of what you've already tried and we'll take it from there.

New at Koh?
Bathroom & Shower Starter Kit has everything you need to get started in one box.

Subscribe & Save with Bathroom & Shower Cleaner
Never run out. Pick your delivery frequency and save on every order with Subscribe & Save.
Browse all Bathroom & Shower Cleaner articles

