VIVOSUN Digital pH Meter, 0.01pH High Accuracy Pen Type pH Tester for Hydroponics, Household Drinking, Pool and Aquarium, UL Certified

This is the second of these PH meters I've purchased. There are a number of negative reviews, so I was a little concerned but went ahead and order one. The first meter calibrated easily and (apparently) accurately. I used the three point calibration, then tested my fish tanks and compared the reading to the drop type ph test kit I had been using. It was spot on as close as I could tell with the test kit. I used the meter for a week, every day on several tanks as I changed the ph. It tracked these changes as I would have expected it to.It worked very well for me so I ordered a second PH meter. (I have fish tanks in two locations.) I then used these two meters side by side. They vary from each other by 0.10 points. The second meter did not calibrate as easily as the first, and the calibration was off slightly. I will try recalibrating, but it's as accurate as I need now. I'm very satisficed with them and would recommend.

This Device worked way better than the junk PH testers I had bought before. The light-up display feature made it incredibly easy to read the display in any lighting situation. So far, it has exceeded my expectations.

Good for low budget testing. However you have to use packets of calibration powder. Not super convenient if you leave it in a drawer for a couple months to a year at a time. But it did seem to test and show results very well.

This product is worthless do not buy it. You're better off buying pH tester strips or saving up your money and getting something better. If you buy this you might as well throw your money away. It is never accurate it is always off by a lot. I couldn't even calibrate it correctly because it was saying my water had a pH of 14. Thats the same as drain cleaner btw. After fiddling with this worthless product for 45 minutes without it being able to calibrate correctly and watching many YouTube videos and it's still being off I chucked it at a wall and and watched it explode that was the best part about buying this product. I will never get this time back from my life could have spent with my kids instead of being violent in the garage.

This product makes t easy to get a good accurate all important PH reading At the time of this review have used it for several grows and it is still durable , reliable and has been of good service

Freshly calibrated, this meter works fairly accurately (within .2-.4 of other sources I trust. I mean, really, for well under $10, it’s bargain! HOWEVER…There is a reason the instructions say to calibrate daily, before each use. After using it about 3 times, in various solutions I found it to be 1.5 units off! But once recalibrated, the circus was back in town and it once again gave accurate readings. But I’m just not willing to go through the calibration hassle before using each time. I even tried a trick a buddy should me where you stuff a tiny bit of cotton, torn off of a ball, way in the back of the lid and very slightly moisten it (6-8 drops?) with distilled water; this is suppose to keep the glass reading probe very slightly moist and therefore help keep it better calibrated.If you’re after accurate readings, and are on a budget, and are willing to pay for extra calibration powder packets, and do the calibrating before every use, this meter might work for you.I returned it and went back to my Biopharm droplet test kit—pretty accurate and reliable (General Hydroponics also makes a good droplet test kit, but not with the .5 increments that the Biopharm reads at).

This is a good buy and easy to use. Mix the reagent with 1 cup water and calibrate with one button. Read my pool pH with one button. I lost my pH probe exactly like this and replaced it with a new one.

Comes with three different pH buffer powders. Batteries inside the tester. As well as extra batteries. A guide on how to use the pH tester. Turned on perfectly and turns off easily as well. I’d recommend this pH tester kit for first timers.