Permeate Go/No-Go Bob?

[Andy VT]

I'm about to start my first season with RO and I thought of another thing to overthink.
Is there sugar in my permeate?
I should no doubt just finally get a sap hydrometer, but it occurred to me that if you just want to know if your permeate is sugar-free, a float or no-float device would do the trick if it existed.
If not, maybe that could be my first invention :D

[littleTapper]

A TDS meter is a valuable tool with any RO.

https://www.amazon.com/Lxuemlu-Professional-Temperature-0-9999ppm-Aquariums/dp/B0B1DHJ8JQ?th=1

RO Bucket folks have a great video on using it.
https://www.youtube.com/watch?v=H7GZLyBHbg4

[Bricklayer]

I have never had any success using a TDS meter for checking sugar passage into permeate.
I check it on occasion with a sap hydrometer. And if I’m really under the impression I’m passing sugar I will fill up a pot with permeate and boil it for 20 minutes then let it cool and test it. I have a digital refractometer as well but I don’t trust it. Think it’s just too accurate for me.

[LMP Maple]

I second the sap hydrometer. I probably check the permeate more than I should but it is easy and fast. Handy as well to have one to check the sap if you don't have one already its good tool that you will use a fair amount.