I had a woman come up to me the other day while i was working on a house and said "does your water leave any streaks, as i always seem to get left with streaks after my husband cleans the windows with my water"
I reply "the water i use is purified to take all the contaminants out so doesn't leave streaks after it dries, normal tap water won't do this"
She then says" yes i know i use the same type of water as you, it was one of the reasons i brought my water softener so my husband could use the water to clean our windows"
She was rather disappointed when i told her that her water softener does not purify water