I Can See Clearly Now

For a while now the mineral build-up on my sinks and showers has been bothering me. I don't have particularly hard water so it takes quite a while for the water spots to form and get noticeably bad, but once they do I find it incredibly frustrating and unrewarding to try to clean them off.

Generally I'll use any of the usual methods: acid cleaners, fine abrasives, scouring pads etc. Inevitably this removes the worst of it, but it always leaves a bit of haze behind still stuck to the glass and tile surfaces. I've searched the internet up and down for solutions to this, only to find useless advice like "lol try vinegar" or hopeless notes of "it's etched permanently".

However, that hopelessness is misplaced, and the surfaces are definitely not etched, and I can prove it in one photo.

This is a picture of my glass vessel-style sink part way through cleaning, with a dark towel behind it for contrast. I'm illuminating the scene with an LED flashlight, the direct reflection of which is just to the left of the image frame.

What you see above is the white cloudy haze I'm trying to get rid of, and the places where I've successfully gotten rid of it. It is most certainly a film on the surface, and one which is softer than the glass beneath it, and the glass surface itself is undamaged.

The secret to peeling this haze off is perhaps the most low-tech solution of them all: wet sanding with 2000 grit sandpaper. It cuts through the mineral deposits with ease, and though it does leave some very fine scratches in the glass surface, they're really only visible under the most harsh lighting.

Same sink, same illumination to the left. If you zoom right in you can see the scratches, but otherwise they basically just disappear.

It also works on glazed tiles. See if you can guess which of these four tiles I cleaned with the sandpaper.

It's worth noting that since the actual glass (or enamel, basically the same thing) surface isn't being notably abraded, you don't need to go up through a range of grits, like you usually would; starting with coarse grits to level the surface and working up finer and finer to erase the scratches from the previous. You can, instead, just go with a single grit to abrade the soft(-ish) minerals from the surface and be left with a perfectly smooth finish once that's gone.