Impossible-to-remove hard water deposits

[Duer 157099]

I will be astonished if anyone can help solve this.

I've tried: vinegar, CLR, anti-rust gels, various other anti-lime products and am now into sulfamic acid.

W.T.F. ?????

There is a very thin layer of calcium carbonate still remaining on the glass shower door, no matter what I try! 3 days soaking in vinegar? Nope. I thought CLR was the ultimate solution but nope, doesn't seem to do a damn thing.

Help? I really don't want to resort to HCl (muriatic acid) but I will if someone knows that will work and won't etch the glass.

This is the most frustrating DIY thing I've ever encountered.

Any creative solution thoughts? I know the idea is to dissolve the calcium carbonate with an acid, but cannot for the life of me figure out why it isn't happening.

Even those magic erasers don't touch it.