$10 DIGITAL ph tester is accurate and lasts?
That is the definition of a contradiction in terms
There is no such things as a cheap - in the $10 range - PH tester that is accurate and lasts. They are never accurate, dont stay calibrated, and dont last.
You need to spend at least into the $50 range for one that is accurate and will last about 18 months. Thats how long a decent PH probe lasts on average.
Note that you will actually save money over time. In 18 months you will spend $90 - almost twice what a decent meter will cost. Plus your plants will be much happier growing in a correct PH environment.
I prefer the slightly more expensive version because you can replace just the probe for a slight additional savings over time. Plus you can get an ORP probe if you are into that.
Apera Instruments AI311 Premium Series PH60 Waterproof pH Pocket Tester Kit, Replaceable Probe, ±0.01 pH Accuracy: Amazon.com: Industrial & Scientific
www.amazon.com
There are lots of other options in the same price ranges from other reputable mfg's.
Edit: Forgot to mention - for any PH probe to last it needs to be stored in a buffer solution. You can use 4.0 calibration solution or some KCL. I use this stuff. A bottle lasts me a year or so. You will also need calibration solutions or packets to keep the meter calibrated. Some KCL and cal solutions will come with Apera sets.
Atlas Scientific pH/ORP Electrode Storage Solution 250ml (8oz): Soil And Soil Amendments: Amazon.com: Industrial & Scientific
www.amazon.com