Refractometer wonky??

[Myka]

Originally Posted by hunggi74

I will get some calibration fluid to retest the water. And I'll make sure the unit is close to 20c when I'm testing. You mentioned that my Rodi unit might be off? As in the amount if TDS in the water is not zero and that the TDS amount is affecting my reading?

I am guessing that maybe your TDS meter is off which implies that maybe it's time to change some filters if you're getting 10 or 13 ppm out of it. What are you using to test TDS? Has that instrument been calibrated recently?