Ross
If you are cleaning windows with a tds of 7 that is why you are getting complaints.
To date i have not lost one customer to the quality of work with wfp.
I have had 3 complaints so far but not about spots ,just because they dont like wfp and those same ones used to moan about the weather , 50p rise etc.
I only ever wfp with oootds . one day i noticed the windows i was cleaning were drying slightly different than normal (Got a trained eye now) I thought thats strange must be something wrong here and sure enough i tested my tds and it read 002.
I think the windows still dried ok but i would not chance anything over 000. I will start another topic for the drying effect with a higher tds
Dave