VIVOSUN 3-in-1 Digital pH Meter with ATC, ±0.1 pH Accuracy Water Quality Tester, 0-14.0 pH Measurement Range for Hydroponics, Household Drinking, Pool and Aquarium

Very bad. Wont calibrate to 9.18. The calibration is stuck between 6.86 and 4.00. Third time i calibrate it goes back to 6.86 and messes it all up. I spent half an hour trying everything. I like vivosun and regardless of all reviews i trusted them but this time they really did me wrong. Returning this product immediately. Lost some trust in vivosun.Go with the $20 pH meters.Wasted 750ml of distilled water and half hour because of this!

The meter works well but the function modes and different electrodes have incompatible maintenance requirements. For example, the storage solution for the pH electrode, oxidizes the other electrodes affecting their accuracy and without proper storage for the pH electrode, it will not retain it's accuracy. It is my thought that to maintain each meter's accuracy, separate storage is required for the Ph meter. So you are better off in the long term to own a separate pH meter and a multimeter for all other functions.

The pH-meter did not work when I received it. It either shows '0000' when measuring any kind of liquid or the numbers on the display fluctuates up and down never stabilizing the pH level. I have followed the manual calibrating it, even though this should not be nessecary according to the manufacturer. The meter can't even read the calibration liquids that came in the package and so this doesn't make it function.Also the light on the display goes dark very fast, so even though one is supposed to wait between 3-5 minutes for the meter to fix the pH level of some liquids according to the user manual - I have to read the result on a dark display since it is not lit for as long as 3 minutes. Not very well thought through by the manufacturer.I live in Denmark and a return would cost more than the value of the pH-meter, so this is not really an option for me becdause I don't trust to be refunded the transportation costs. Also it is not very sustainable or environmentally friendly when I could just email both photos or photage of the defect product. This should be evidence enough to refund med.

As far as mid-range ph meters this is a decent meter. I had decided to upgrade from the black and yellow ph meter to this one and when compared its night and day. This meter has a backlight which I love it came pre-calibrated off by maybe .1 or .2 nothing that would really effect anything when re-calibrating was super easy with RO water. I tested this side by side my cheap black and yellow (11 dollar) ph meter and could deffinatly tell i needed a upgrade the black and yellow would be completly off even after re-calibration this one held calibration through and through even after doing several ph readings with diffrent liquids and water no issue. the PPM I couldn't really tell as I compared it with the blue reader ( cheap one) and came out basically the same so I can assume its accurate out of the box.

Vivosun stands behind their products. I used this meter for 6 months and it quit working. Customer Support refunded my purchase price. So I bought another. Accurate measurements. Excellent tool at a very good price.