Which shower wall/floor should I take?

Isn't a type of mold also red?

It’s not mold, then probably iron deposits. I can take a photo sometime :rolleyes:

Yes, that is usually iron. We had that in our apartment too.

The image is heavily edited so that anything can be seen at all...

Is there a special joint mortar for the shower so that neither lime nor iron nor anything else sticks to it?

and tiles not?

We think: Obviously - wipe off tiles + glass after showering.

It only takes seconds - but everything is always clean.

Soap residue/shower gel deposits are a nightmare. Everything unwanted "grows" on them.

After showering: Clear water on all walls, then just clean with the squeegee. What's the problem?

We have excellent, quite low-lime water here.
That makes it easier - I only do a deep clean of the showers once a month.

Red deposits: iron in the water.

In every shower we have tiled 2 walls, 2 with glass.
The maintenance effort for the walls there is equally high for me/us regardless of the material. And - we are very meticulous about cleanliness (especially I am terribly picky about it).

--> Matter of taste whether stone or glass.

Best regards
Thorsten

..or cost issue :confused: