Total Dissolved Solids (TDS) reading on permeate

[82cabby]

Hi gang-

I got myself confused and ran a RO soap cycle with tap water. I know, I KNOW. I was tired and got two buckets confused.

Today, running sap through them, using a basic handheld TDS meter to check the permeate, My 4x 150gpd setup has a reading of 2ppm and my 5x 400 setup is reading 6 ppm.

Season is almost over so I’m going to keep plugging away but do these readings indicate anything terrible about the membranes? Obviously zero is ideal but how far off the mark are the readings I’m seeing?

[DRoseum]

6 ppm is still low. They should be fine.

[ecolbeck]

6 ppm is still low. They should be fine.

What upper limit should we look for?

[DRoseum]

I wouldn't be worried under 20...or Maybe even higher...a higher number obviously is indicative of some minerals passing thru, and potentially sugar (which isn't detectable by conducitve/resistive TDS meters).