MacDoDo PH-02 Digital PH Meter Tester Best For Water Aquarium Pool Hot Tub Hydroponics Wine - Push Button Calibration Resolution 0.01 / High Accuracy +/- 0.05 - Large LCD Display (Yellow)

It only lasted a two weeks and one usage. It arrived calibrated and functioning. After the first use, I cleaned it with distilled water, as instructed, capped it, and, since I live in the desert, stored the entire tester in a sealed jar to be sure it wouldn't dry out. On the second use, it was clearly miscalibrated. I recalibrated it using premixed ph solutions from lab bottles. It couldn't produce a reliable reading no matter how I tried to calibrate it. It would lock on 7.00, 0.00, or fluxulate wildly in the high acid range, even in distilled water.You get what you pay for. I should have bought a big box of test papers. At least they are reliable.I was using it for kombucha brewing

This piece of hardware is sold under numerous different brand names on Amazon. I believe the only real difference is who does the factory calibration. When I received the MacDoDo tester, I used the buffer packets to test and recalibrate all of my testers*. Except this one was already spot-on, so there was no need to recalibrate.* I need more than one because I don't take good care of it and I need to know when it goes out of calibration. I never wash with distilled water after using it to test the hot tub because I'm busy tubbing. In the long term, I expect this to damage the electrode enough to require recalibration, and the way I check is to sometimes use a second tester. I have 3 now because I thought I had ruined one, but it turned out I only ruined the batteries.

Arrived with a buffer missing. Read the calibration instructions but could not understand them. Went through calibration process with the other two buffer powders but could not calibrate. Examine tool carefully. This was made in China and is really junk. There were many others available from others that look exactly the same. I needed mine for aquariums. Back to other methods.

Worked pretty well for 60 days, but suddenly began giving wild measurements immediately after that. I bottle Kombucha so need to verify pH levels throughout fermentation. It's not an expensive instrument, but still should have held up for longer than two months. It comes with a 1-year warranty so I've reached out to seller Modernway and hope to update my review shortly based on their response.Updated Jan 2017 - Modernway's customer response was GREAT as they immediately shipped a replacement meter & it seems to be working fine. I'm unable to re-calibrate the original meter so assume it's an overall malfunction. Be extra careful not to press the calibrate button vs. on/off during use as I suspect that causes problems with the electrode. I'd recommend buying.

I was unable to get accurate readings with this meter

works great, required calibration is a bit tricky.

I tried to calibrate at exactly 25 C, it would calibrate and then I rinsed, dried, and took readings again and they were way off. I tried this multiple times using all three solutions and could never get it calibrated.Last time I tried to calibrate it got stuck reading 7.00 and could not get it to read differently at all.

Seems a little jumpy and takes some time to get a good read out... using for fish tank so just giving a ballpark range for me is fine.. overall good product for the money.