Any update here? Mine seems low as well. Calibrated a few times, reads 32 or 33 ppt, should be 35ppt. On top of that, the cal solution seems not to be consistent. Calibration clean, rinse in ro/di recheck cal and its easily another 1.5 ppt or more off. Not sure whats going on here.Mine is way off. Both (fully recalibrated) BRS refractometer and digital controller probe show 1.025 (where its been since day 1), I have used 3 packets of Hanna recalibration liquid and it still reads 1.022. I tried both in the tank and a new mix for watrer changes, same result. It is consistent, but inaccurately consistent. I will call Hanna tomorrow to exchange for a non defective one.
Temp is off 1 degre, i think.