"Pure Water Window Cleaning" does not use any soaps to break up the dirt on your windows. Ultra-pure water, which has a TDS (total-dissolved-solids) reading of 0 (zero) is "created" on-site and used to dissolve and rinse away the dirt on your windows and frames.
We use the term "created" because water with a TDS reading of 0 does not exist in nature. "Ultra-Pure Water" is aggressive when it comes to removing dirt, because it chemically seeks out dirt to bond with, as water wants to return to it's naturally dirty state. However, it is completely environmentally safe!
Tucson's water has a TDS range from around 300-500 (which is considered very hard, but not as bad as the 1000 range in Las Vegas). Thus a multi-stage purification system is needed. Streakless Windows uses a 5-stage purification system to purify water, which is then pumped up a Water-Fed-Pole through a small hose to the brush, which scrubs the windows and frames. After agitating all of the dirt with the brush, the dirt that was on the window, having been chemically bonded to the pure water, is rinsed away.
You will notice that the windows are not squeegeed after being cleaned. Fret not, although you will see water drops on the glass outside, THEY WILL DRY SPOTLESS!
MYTH: RAIN MAKES WINDOWS DIRTY.
FACT: DIRT MAKES WINDOWS DIRTY.