Hello SteveO 
I think that here in Belgium we have too many window cleaners who have already done this the wrong way, which has frightened many people.They immediately think that there would be too much limescale.
I believe in the system.
Too bad that many simply can’t handle it !
Here they still work a lot with ladders. The company I work for also does this. They had a system but they no longer use it.
Still a nice and for many an interesting video. 
Keep it up!
greetings from Belgium 
In NE Tennessee, I haven’t had any issues with being able to use it. My TDS averages at about 40 ppm- 120 ppm. There’s one job I have that is about 220 ppm. I use 2 DI tanks that are 1/2 cu’ each and they work great!
I simply tell people that the tanks filter out all the sediment from the water, as that’s what leaves spots behind. I always make sure to talk about it with excitement and I say that its really the best thing to come around to the industry.
People always respond well to you being excited about the work they’re paying you to do. Lol!