I've been learning and applying the TFP techniques for several months now. With all the great support/hand-holding it's working well for me in all areas except one and that's the pH test. For some reason this is just very difficult for me. I do all the others with ease. I also have a lot of lab experience but I always used a high dollar meter that cost $$$$$. From what I've read here I think other are having this issue as well. I found a solution that is really working superbly for me so I thought I'd pass it on. I bought a battery powered digital pH meter and a bottle of 7.0 pH calibration fluid. Each were less than $20. I used the digital pH meter at the same time as I do the color test. Over just a few days I got waaay better with the color test. It's really been a great way to teach me and give me confidence of my red shade "interpretation". I calibrated the pH meter frequently at first but I was amazed that it only needed adjustment once over the past 8 weeks. Now I'm able to rely on the color test with confidence and if I'm ever not sure I do the pH meter as a back-up. I know cheap pH probes haven't been reliable in the past but new sensor technology and electronics have made these new ones way better.
The calibration fluid and meter were under $20 each and I think you could buy a smaller bottle of calibration fluid to save money. I've only used a very small amount of my bottle.
The thought of spending $35 just to learn how to do this test won't be for everybody but I've saved WAY more than that by taking over the pool so it was a good idea for me.
I hope this helps somebody. And if you want the brand details let me know. As far as I can tell many of the pH probes look identical and the one I bought is probably sold under several brands.
PS my pH today was 7.8! And I'm sure the number is correct!