I've been in business now for about 3 months, and thanks to the advice from this site, the efforts of Paul Bass, and the co-operation of some friendly local window cleaners things are going great.
After reading a few posts though, I'm intrigued by the idea of using Pure Water for traditional window cleaning. I've got a friend who could provide the water for me, and I've splashed out on some GG4 ... but is there any difference in technique to using Fairy Liquid-ised water?
What are the marks that everyone keeps mentioning, that occur in low-level sunlight?
Also, how do I make sure that the water I'm storing remains pure and doesn't return to it's original state, or more worryingly develop some strain of Legionnaires in the blisterin summer sun we're all looking forward to?