I have a hardwater stains on my bathroom shower tile. I have tryed to cleen them but nothing.
Acid. Scale will dissolve, grout is much more resistant. L
As caarntedd says, there are paints that will stick to tile. I have yet to see painted tile that didn't look awful, though. I'd suggest trying every cleaning option available before resorting to paint. Steve's vinegar idea really should help with hard water stains, as would a CLR-type cleaner. I believe Tilex makes a formulation for hard water stains as well. If you haven't tried some of those, do give them a shot before painting.
+several on the awful appearance of tile paints. Not nice at all.
There are products available for painting bathroom tiles. Just google it.
Have you tried mild acids, like distilled vinegar to clean the water stains ?