Review on High Accuracy Pocket Size Digital PH Tester Pen for Water Hydroponics - 0.01 PH Measurement Range Ideal for Household Drinking, Pools, and Aquariums (Blue) by Amy Mcleod

Good day readers of my reviews and not only. I would like to share with you my impressions of the PH meter with Ali Expressa. I bought it to measure the pH of water. As is known in hydroponics and aeroponics, this is the most important factor for the preparation of the solution. And so: for calibrating the device with a PH meter, two bags of powder, the so-called space powder, came. One of them with PH - 4.01 at 25 degrees Celsius. Another with a PH of 6.86 is also at 25 degrees Celsius. Yes, by the way, the instruction that came with the device is in English. Therefore, the stages of verification of the device were taken from the Internet. Each powder must be diluted in 250ml of distilled water. Before each measurement, you need to rinse the electrode of the device well, also in distilled water. Then make the next measurement. This device, I don’t know why, showed a deviation in both cases of measurement by 0.21 PH, i.e., where it was 4.01 for a long time, it showed 3.81. Accordingly, where it should be 6.86, he showed 6.65. I do not know what it is connected with, maybe with the quality of distilled water. Or maybe with the quality of the device itself.