Hi all i need some help please, i have just started using a w.f.p. and i think i have the basics. I do have a problem, i did a few houses this week with the pole and when i collected i asked what they thought of the clean they said the windows wher clean but there was spotting on them. Now i checked the t.d.s and it has never been any higher than 5 so t.b.h. im stuck am i missing some thing in the way im cleaning!?? please helpl!!