TDS numbers

So today as I was finishing up a 2 story with the WFP with my Unger Hydropower and I noticed I was up to about 68. (185 going in). Lots of sunshine here today in Florida and the windows dried spot free.
This afternoon I’m going to wash the van with the WFP before I swap out the resin bag to see how the windows hold up spot free since I will be looking out of them everyday.
What is the max TDS you have used?

I never clean with more than 5-10 ppm. Now I have a RO-DI, but while I was cleaning with my Hydropower I checked the TDS every half hour. One time an employee forgot to check the tds while he was cleaning in a hard water area and it went up to 180 ppm…I think I don’t have to tell you how much work that caused. If i clean with pure water I want pure water otherwise there will be something left on the glass…maybe you don’t see it after the first time, but after a few times? Don’t try it out.

Hey Garry! 68 is high for sure, of course as been mentioned before its not just the number but also what the particles are in that number. For us in KS, the iron is quite high in my area and we have to change out our sediment filters very regularly to preserve our RO. We have only used up to 18ppm since we carry our water we now can catch it long before we ever get to the job.

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Yes, I have heard that 10-17+ should be avoided, but have also read elsewhere that up to 95 can be used, depending on what is in the water. I am also sure to tell all of my customers that I 100% guarantee my work, and a simple phone call gets a complimentary clean of the offending window to their satisfaction.
Edit: with Florida’s sandy soil and limestone aquifer we don’t deal much with iron.

I get 58 out of my kitchen tap. It’s one of the benefits of being in Scotland. Only need a di and it come out at 0-1. I have used upto 14 and have heard of people using upto 30 with no issues. Just need a good scrub and rinse.


It read 38 on the Hydro unit just a bit ago as I washing the van; 17 with my handheld TDS meter coming out of the brush. Put in a fresh bag after cleaning the van so set to go for Tuesdays job.