Review on Hydroponics Accuracy Measurement Household Drinking by Lindsey Braaten

I have to say the customer service is commendable. After the feedback below, the seller contacted me and sent a replacement unit. This new unit appears to measure effectively, but does not provide instant readings. Leaving the probe in the liquid for about 30 seconds will stabilize the reading. I have verified the accuracy of the readings using a chemical color test and comparing the digital readings from this device to a color matching solution. I have not attempted to calibrate the new block as it is currently showing accurate readings and I don't want to push my luck. I am satisfied with the subsequent communication from the seller. Right out of the box I tried measuring my Ro/Di water and got sporadic readings. I tried to calibrate the meter but the meter wouldn't go into calibration mode. I contacted the seller who repeated the original instructions to me. I tried again to enter the calibration mode without success. The meter is not working and cannot enter calibration mode.