How to remove soap scum on glass shower that has been there for years

https://www.youtube.com/watch?v=acfA3epxI-s

Mr Clean eraser?

Magic eraser? 0000 steel wool?

Repeated applications of CLR and a lot of scrubbing.

Check your local auto parts house for a window cleaner meant to remove the spots. Clr woukd probably work well too, but you gotta be careful for the rubber seal and paint

https://www.hometalk.com/diy/clean/bathroom/remove-soap-scum-with-a-grapefruit-and-kosher-salt-28708364?r=2

Have you tried toothpaste yet? It cleans oxidation off headlights, so it might work on shower doors. What do you have lose? Here's how to clean the headlights on cars ... try it on the shower doors. Good Luck. If you decide to try it, let me know if it worked (I don't have shower doors so I can't try it, but if it works for you it will work for others too). Thanks for asking Hometalk for suggestions :)

https://www.yourmechanic.com/article/how-to-clean-oxidized-or-cloudy-headlights

Try toilet bowel gel.

1. Use gloves
2. Ventilate area; bring a portable fan if necessary
3. Make sure glass is dry, dry, dry
4. Spread toilet bowel gel cleaner on wax paper pieces. Make the pieces of paper in workable sizes. Too big and it's difficult to work with.
5. Tape wax pieces onto glass.
6. Wait at least 2-3 hours before removing.
7. Rinse and dry well.
8. Use car paste wax and cover entire glass.
9. Buff out.
10. Reapply wax once a month.

If the scum look still remains, the hard water has etched the glass and it's not soap. Use silver polish to remove. Use wax as above. Good luck.

Bar keepers friend liquid cleaner will work.

Borax 1/2 cup , 2 cups cleaning vinegar (in laundry idle at Walmart must say cleaning strength), 1 cup HOT water and 1 Tbps dr. Bonners peppermint hemp soap make solution in spray bottle and make sure it's completely mixed together, then spray it on the surface and leave it8+ hrs or longer. Respray solution after sitting and use soft brush or sponge to remove then rinse completely

Lemon Oil furniture polish. It may take several applications but it will work. I wonder if WD 40 would a.s well...hmm

I absolutely LOVE a product called Sanivac. I lived on a well and an old old house. Worked perfectly!!