White powdery film appearing on tiles when rub them with your hands

Hi
The tiles in shower in our ensuite seem to have a white dusting film on them that appears if you rub the tiles with you hands.

It seems to rub off if you rub it with a dry cloth

The shower tiles are sprayed each time we use it with one of those daily shower sprays out of Aldi/Tesco and about every couple of weeks we wash the tiles and the shower like a deep clean

Whats this white residue/powder. Its not grouting as its a few years sinced the bathroom was done up

Any thoughts re how to get rid of this and keep it away or is it just dried out soap/shower gel/daily shower spray residue and just needs to wash the tiles regular in warm soapy water

Thoughts
Thanks

P.S Have tried to upload pic took of this but dont seem to be able to upload from PC

Hi Passport. It sounds to me that it might be a residue from the time it was grouted. Try this...... Thoroughly wipe just a few of the tiles with a wet and dry cloth and and compare them a few days later to the ones you didn't wipe. I reckon the tiles you wiped should be ok. If not, check to see if the powder is coming form the lines of grout.

It could very well be residue from the cleaner you are using. try alternatives or the Kim & Aggie style DIY solutions.

If the grout was the source of this, you'd have no grout left at this stage.
Leo

Could be a lot of lime in your water, does it go on the glass enclosure also?

Is it hydroscopic salts from rising damp?

Thanks for all the replies and advise
The tiles affected are isolated to the shower area. Other times in the bathroom (all the walls are tiled floor to ceiling) dont seem to have this residue so it could be comething to do with the shower cleaner.

The glass enclosure gets streaky too but doesnt seem to have this powery residue on it

Gave it a good clean over the weekend and seem to have got rid of the powdery residue - will keep eye on it and see if it comes back

Leo - what are the Kim and Agie DIY Style solutions you mention or where online would you find them listing and how to make them up

Thanks