DI resin expired already?

[hillegom]

Is it a dual inline tds? They can be calibrated, but it comes calibrated from the factory and 3 months is not a long time. Unless of course, it was bounced around during shipping.
Maybe the LFS would check it where you bought it with their water.
But even 1 ppm is not very much. Some people are using tap water without any trouble
(not that I would recommend this though)

If you have a dual tds, what is the tds of the incoming water?
What is the tds of the exiting water from the membrane, before the DI?