Recommend a pH meter?

I have the milwaukee mw102. It's a little expensive but worth it because it adjusts the ph to the wort temp. I also use the milwaukee storage solution that keeps the ph calibration almost perfect.

 

I have this one that I got in a lamotte water kit:
https://www.amazon.com/Oakton-EcoTe...1?s=industrial&ie=UTF8&qid=1474979859&sr=1-11

It's served me really well for 4 years now…very easy to calibrate and to use. Waterproof is a huge bonus. Just keep the probe in buffer solution and it works beautifully. Just tested my souring saison last night…currently at 3.8.

 

I bought a 17 dollar pH meter on Amazon (slightly different model) and I think it's the best way to start your quest. It did an okay job for about a year and then gradually starting taking forever to accurately measure the pH of the mash . . . sometimes not stabilizing until half way through the mash cycle. I'm sure part this was because it was cheap and it finally bit the dust.

There's a learning curve to using a pH meter just like any brewing technique. My experience is they are complicated to maintain/calibrate . . . things like buffer solutions, calibration liquids, ATC can be persnickety. Starting cheap and ultimately tossing a cheap-o is less traumatic than the opposite.

Recommend getting involved with massaging your brewing software to let it help predict your mash pH. Then after learning with an econ model maybe step up to something nicer.