Distilled white vinegar full strength might work.

Unfortunately, no, they are usually coated on the inside only, unless you specify otherwise.

"For most shower doors, the protective coating (spot-resistant, hydrophobic, “easy-clean,” etc.) is applied to the inside surface, the side that actually gets hit with water, soap, and minerals. That’s where spots and buildup are the worst, so that’s where the coating earns its keep.

• Factory-applied coatings (like ShowerGuard, EnduroShield, etc.) are almost always one side only unless the manufacturer explicitly says otherwise."

" could it be that the glass is coated on only one side? "

100% it definitely is only ONE side. As Diana Bier Interiors, LLC pointed out above.

OMG....I really made a mistake hiring this contractor!

Sounds like it. There are aftermarket protectants that you can apply bit they will need to be reapplied periodically. However now you would sealing in the deposuts already there. I would clean the glass as best as possible (people here can recommend what works good for them for mineral deposits) and then seal the glass.

What does your contract specify? It looks to me like the contractor owes you new glass, properly installed. At his cost, not yours.

My contract just says size, orientation, and glass coating (Diamond Fushion).....he did the orientation wrong (and came out and reversed/corrected)...and ONLY then did I start using the shower and found that the marks from the water could not be removed with non-ammonia glass cleaner!! None of the coating companies would tell me if they only coated one side. No thing in the contract says ONLY interior of glass will be coated....Maybe that is just assumed?

The orientation is still wrong, because the coating is now on the wrong side.

The whole point of contracts is that nothing is assumed. Everything is specified.

the problem is that the orientation that I ordered was not honored. They made the doors with the handle facing inward instead of where you can use it to enter the shower and coated the glass to suit the incorrect set up ....I will sort it out.

Can the doors be returned to their previous orientation and the handles reversed instead?

MILLWORKMAN: GOOD CATCH!! Strangely enough, the glass panes are oriented correctly AFTER the panes were reversed per my initial quoted. both doors slide so even if they were overlapping in the wrong direction , they could be slid into the correct overlap direction.