Digital pH and TDS Meter Combo, High Accuracy 0.01 Water Quality Tester and 3-in-1 TDS and EC Meter, PPM and µS Meter for Water, Practical Water Testing Kit

Make sure you have distilled water when you use this or any other pH meter. Calibration is recommended before use and the probe needs to be rinsed with distilled water after use. The pH meter should be calibrated prior to use. As a test, I read the pH of a water sample before calibrating the meter. It read 7.22. After calibration, it read 7.10. Recalibration is not required under most circumstances, but the instruction pamphlet does tell you to mark the buffer solutions that you made so you can recalibrate later. Unfortunately, there is no mention of shelf life or storage conditions for your buffers. The powdered chemicals to make the buffers are included, but you're going to need 1 to 3 cups of distilled water to dissolve them in. After calibration, you're good to go and just have to follow the use and maintenance instructions. The pH meter takes a little while for the reading to stabilize. That's pretty standard for devices that test water. The second meter in this kit is for TDS (Total Dissolved Solids), EC (Electrical Conductivity), and temperature in °C and °F. The temperature function is probably the most useful feature of this probe. This probe is low maintenance, just requiring you to clean the electrode after use and replace the cap. As for cleaning the electrode, I just fold up a paper towel into a little point and twirl it around each electrode rod. If I were putting the sensor in something dirtier than tap water, I'd also rinse it off before drying it. Technically, I should probably be washing the electrodes with distilled or DI water after each use (that's from my previous experience with meters like this, not that the instructions say to do so), but for everyday noncommercial household purposes, I'm not going to be bothering to do that. Temperature is correct. TDS is at least in the correct ballpark although I have no way of saying exactly how accurate it is. I'm not sure about EC. The temperature reading changes continually, but the TDS reading will stay on the meter even after you remove it from the liquid which can make reading your result much easier. Overall, I'm happy with the ease of use and quality of these meters. Readings are accurate according to litmus paper and testing of the buffer solutions after calibration. I ordered this set because I'm getting into hydroponics and aquarium set-up and you really should know pH for both of those.

Both ph meter & tds meter both are inaccurate & ph meter will not keep an accurate reading no matter how many times you try to calibrate.!

I am giving 3 stars. The ph metor they gave instructions ans solution to calibrate it. The tds says it needs calibrating but no instructions. Instructions for both would be great. I need to a book to know how to use or what the numbers mean. I guess if your a chemist you would know.

I could have used more instruction on how to interpret the readings.

I had another set for over a year, and it slowly got ruined. This one is a great replacement. I calibrated it, which is pretty simple, and we're good for a season. I use these for my water reservoir. It's 12 gallons with air stones. I mix nutrients in a 1 gallon milk jug then pour into the reservoir. Then I wait 10 minutes, and then check the pH and PPM's. This thing is easy to read, and pretty accurate pretty quick. I like it.

I first checked the TDS value of my tap water and it gave me a 24ppm. I had checked the water with a TDS meter my friend lent me a few months ago and it was 25ppm. I take this to mean that the values from this TDS meter is pretty good and my tap water is pretty good too. My EC at 22.1C was 52, which I think is pretty good too. My understanding is that you are suppose to compare EC values at 25C, but that's for the experts to do. I just want an idea of the quality of my water. I tested the PH meter with vinegar and my PH paper strips and the PH meter seems to be pretty accurate as well. There is a calibration process for the PH meter, but for now I'm comfortable with the values I'm getting. This is an easy to use and helpful test kit for a very reasonable price point.

Works as intended and is better than using copious amounts of Ph testing strips.

I didn’t get any probe with mine. I searched “Ph meters for food” as I wanted to use it for canning, sourdough but this doesn’t look at all like what i need so will be sending it back asap.