[Neil271052]

A customer of mine has been hosing her plants and has left spotty water marks all over the glass that ordinary cleaning will not remove.

Any ideas?

[Feen]

What's she been hosing them with?? Paint If they are resin type deposits from the plant, try a scraper and tell her to stop doing it

[john tomkins]

I've tried myself with limited success both Cillit Bang and MDR (Mineral Deposit Remover) someone posted on here that this will shift anything but I've yet to try it 
http://www.windowcleancentre.co.uk/productdetails.aspx?ProductID=186&SectionID=40

[nat]

that was me john and the stubborn water marks i had it took off straight away where everything else failed, mind you mine was a big commercial that was worth a bit of money, to do it on a house you will need to think of the cost!!!!

[windowwashers]

A customer of mine has been hosing her plants and has left spotty water marks all over the glass that ordinary cleaning will not remove.

Any ideas?

tell her to stop watering the windows would be a good start, and charge her to get the spots off.

[Neil271052]

Thanks Gents. 

[Jack Avery]

If its limescale Malt Vinegar. If its a chemical feed in the watering system -- it will come off with time and effort.

kind regards
Jack Avery