Review on 🌡️ Highly Accurate Digital pH Tester Pen for Water Hydroponics – Pocket Size, 0.01 Resolution, 0-14 pH Measurement Range – Ideal for Household, Drinking, Pool, and Aquarium (Yellow) by Andrew Dickens

I returned this garbage. I have very alkaline tap water. I've known this for a while and bought this pH meter to deal with this situation when I was trying my hand at hydroponics. I took it out, followed the instructions and washed it with distilled water. Then I did the first tap water measurement. The reading was erroneous, but averaged 4-5. Remember my tap water is alkaline. So I figured I need to calibrate it and everything will be fine. So I carefully followed the instructions (which are TERRIBLE), put in the 6.86 solution and, while holding down the CAL button, calibrated it for 4.0. Lol now it reads my tap water at 0.38 hahahaha! I thought I was doing something wrong. I went to YouTube and found the videos that everyone is talking about. Your procedures didn't work either, you can't choose what calibration you want on the meter. He chooses for you. And if you have a WILD block out of the box, you can never calibrate it. GARBAGE! DO NOT BUY! ONE STAR IS TOO HIGH, RATE NEGATIVE STARS IF POSSIBLE. If you need a good pH meter, do yourself a favor and spend your money on a good one. There are no shortcuts with these cheap Chinese toys.