VIVOSUN 4-in-1 Digital pH Meter with pH/TDS/EC/Temp Function, 0-14.0 pH Measurement Range, ±0.1 pH Accuracy Water Quality Tester for Hydroponics, Household Drinking, and Aquarium

I usually use a different meter...but that one was not working (I had let it sit too long and I could not calibrate it) so I went looking for a good meter. I landed on this one as it was highly recommended, so I figured why not. So I began my grow Back in Sept with this dual pen and as you can see, it's been amazing throughout the entire grow. I am about a week out from harvest. When I say she works really well, I mean she works really well! You do kind of have to get used to calibrating it but after that it's a breeze. If you need a good pH pen and a TDS meter, I highly recommend you grab yourself one of these.

Accuracy was good for about 60 days. I’m sure I got a defective one though. Now my pen will not calibrate.. Hopefully they honor the warranty. I will up date. I emailed Vivosun and they sure did send a new one. I’ve bought multiple products from this company and they stand behind the warranty’s on their products. Super easy warranty claims. I have an older model PH meter that i bought 2 years ago and it is still supper accurate.

It does need to calibrated for ppm as well as the ph. And I didn't know what I needed for solution til after I got it and read directions. I had got what I thought it would be and I only got 1 out of the 3 you need correct. So had to buy more solution because it only comes with the ph calibration kit. Then the ph is off slightly and jumps around alot but if you let your water set for a few hours it seems to be more stable so maybe it is just that sensitive. But all in all it does work pretty well. And you can't beat it for the price. For what it has for function I'm very happy for what i got.

So, I got this meter and it came with a dry electrode and I was wondering if maybe it was a returned one. I read through their instructions and found that no, it was definitely not a return. Anyone new to pHing or hasn't had the opportunity to talk to someone like a chemist (I have) about it, do some research on care of a pH electrode. First the manual says to rinse it with purified water when calibrating. That's a broad term. You need distilled or reverse osmosis that removes the total dissolved solids (some reverse osmosis systems add back in TDS because not healthy to drink without) or ions in the water to not contaminate it, the pen reads the pH from those ions, which you don't want extra on there when calibrating or storing. Second, the manual says to rinse with purified water and dry the electrode and store it DRY!!! Look up what makes a pH electrode go bad the most... leaving it dry. Also electrodes have a shelf life even with proper care. You'll be lucky if you get a month out of this being accurate. Mine lasted a day and needed calibration between every reading. Returning. This company knows nothing about pH electrodes.

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.

I’ve had a lot of meters that quickly crapped out, this one hasn’t let me down. Accurate, affordable, and lasts.

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.

Product broken only few months in. I use it evwry othwr day for qatering but for 40$ id expect a little longer use. Ive gone through 2 pens already this red one and a grey one. Recalibration does not work. Pen is 100% broken i went to website for troubleshooting and on youtube. I always buy vivosun for all my garden needs. But might not ever buy a pen from them again...picture is the same solution. Couldnt get video it spazzes out from 2.00 to 5.00 ph goes everywhere