Digital pH and TDS Meter Kits, 0.01pH High Accuracy Pen Type pH Meter ± 2% Readout Accuracy 3-in-1 TDS EC Temperature Meter for Hydroponics, Pool and Aquarium, Black White, UL Certified

After reading several reviews on this and other similar models I decided on this two pack PH and TDS. I recently installed a reverse osmosis under kitchen sink with a tds digital display and wanted another way to check its accuracy along with what ph the RO water was putting out. Item arrived quickly and after reading instructions I decided to give it a test. Batteries were already installed and additional batteries were included so that and they both were already calibrated so two pluses from the start. I filled a glass with reverse osmosis water and another from bathroom sink. Tds for bathroom were 107 compared to RO water of 9. This is the same reading my RO system shows so I assume its pretty accurate. Next I tested the PH. Ro water was higher than bath sink water but this units numbers jumped around a bit. Although the numbers did not display steadily i was able to get a good reading and am pleased with the results. For the price I find the two units a great bargain and much better than the water test strips I was using. After my initial tests I highly recommend these products as they appear to be accurate and easy to read.

The ppm meter comes ready to use, the pH meter needs to be calibrated before use with the provided materials. It works well and is pretty fast.

Great value for the money., easy to use, but would like more information on the readings. Very easy to use Compared to other products this was a great buy. Shipping was fast., good value.

Vivosun Digital pH and TDS Meter receive a 5-star rating because of the customer service, and the products. The pH meter was not working when we received it. I contacted Vivosun and they offered a refund or replacement. I went with the replacement and received a new pH meter the next day. Both meters are working, now I just need to adjust the pH in the water I am giving my herbs so we can all be happy.

So I bought this set wanting to try out actually tracking and adjusting my pH and EC of my nutrients for my little indoor hydro-farm. Like most people, I didn't want to spend a lot on my little hobby so I figured I would give this product a try as I actually enjoyed some other Vivosun products. I'll start with the TDS/EC Meter. It is actually decent and appears to be pretty accurate right out of the box. I've used it for a little while and it remains to be acceptably accurate so far without any issues. Good to go, this one I'm pretty happy with and will continue to use at least for now. Next I'm moving on to the problem child, the pH Meter. Wow. Where do I begin. I started off trying to figure out how to calibrate this little thing as the instructions drastically varied from all the calibration videos available online for it. Maybe they changed the method but once I figured out how it wanted to be calibrated I went through the steps and all was good. I tested it a number of times using various testing liquids and it was pretty spot on (at least within acceptable limits for my hobby, not anything that needs to be precise though). So I mixed up some of my nutrient solution, cleaned the pH and TDS meters as advised to in the manual and put them away safely. Fast forward 1 week, I pull out the pH meter and dip it into a cup of distilled water and it tells me that it has a pH of 10.3! Far from the value of 7 I was expecting to see. So I pulled out my other pH balanced liquids to test and every one of them was extremely off from what it should be. It completely lost ALL calibration after one use, and one week of storage. I'm sorry but that means I need to calibrate this thing every time I turn it on? And they only supply you with one set of calibration powder that isn't to be re-used? Absolute and complete garbage. The calibration costs for a year would be well into the hundreds a year for a $10 meter! Absurd. This is a product you should definitely skip buying. Buy yourself a 14-sided dice and give it a roll, it will give you a more accurate guess on your pH level than this thing every will. I would return it, but I was not thinking and threw away the packaging already.

The VIVOSUN digital pH meter is easy to use and gives quick readings, which is convenient for basic testing in hydroponics, drinking water, or pools. The pen-style design is compact and portable, and the display is clear and easy to read. However, the accuracy can be inconsistent unless the meter is calibrated frequently, and the readings may drift over time. Build quality feels somewhat lightweight, and for more precise or professional use, it may not be fully reliable. Overall, it’s an acceptable 3-star product for casual or occasional pH testing, but it may not meet expectations if you need high accuracy or long-term stability.

Accurate, it comes "pre-calibrated" for accuracy, though they also include 3 little foil packets of buffer powder to re-calibrate. But the 3 packets are for different pH levels. You can do 3 calibrations for 0.01 accuracy, but I would have preferred 3 packets of the pH6 buffer.

I picked up this set to help me get my Kratky mason jars tuned correctly for the herbs I’m growing indoors; mostly oregano right now, plus a few other experiments. For something this inexpensive, the meters have been surprisingly useful. I looked up the pH and nutrient ranges my herbs needed, mixed my A+B solution, and then used these meters to tweak things until everything landed where it should. The readings have been consistent so far, and they’ve made it a lot easier to keep my jars in the "happy zone" instead of guessing and hoping for the best. If you’re getting into simple hydroponics or just want a straightforward way to check your levels, these do the job without any fuss. My plants certainly seem to appreciate it.

La calibration est simple. Par contre, par rapport à une sonde témoin, il est extrêmement lent. Il faut compter presque 10 minutes pour que le pH final soit affiché. Il faut donc le mettre longtemps pour à avoir le bon pH. Après 6 mois et une utilisation par mois, il deconne complètement. Mauvaise qualité

Arrived not working, tried replacing the battery but no joy so sourced an alternative

I bought this set mainly to check the conductivity of my LC coolant in my Ioniq 5. The items arrived quickly and safely in a solid box. It came with full instructions and even an extra set of batteries. I checked the TDS meter using tap water and got an expected reading of 56 (pure distilled water would be closer to 0) us/cm. I am very pleased with the performance and the value. Highly recommended!

TDS meter are working fine but for the PH meter I personally don’t arrive to fully calibrate it as all the time I do the PH 7 then PH 4 and when it’s arrive to do PH 9 it’s return to PH 7 so impossible to complete the calibration.

Al tratar de calibrarlo en la solución 6.86, se activaba el calibrar pero tardará mucho parpadeando y cuando paraba aparecían las letras, Err y de ahi no pasaba..