Well I know I and others have worked with very high TDS values already. With fantastic success. And I know why we had that success. I think there really is almost no limit to the TDS based on different conditions that we are still working with. I invite everyone to join me on my facebook group. Or here. This thread is perfect for exploring this technology. Here are three different conditions that will give you success. First convert the glass from hydrophobic to hydrophylic with a bronze wool pad. Second use a superwetter at a percent of .01. Next work on a cloudy (no sun) overcast high humidity cool (55 degree) day. Check your TDS with a meter before experimenting. Use a small window maybe a two by two foot. You can use a hand held garden sprayer. Convert to a laminar flow. This is to eliminate all suds. Suds will leave soap streaks. Even from a .01 % concentration. My Super Soap of choice would be a silicone based anionic.