I understand that the acid / base demand test can have value under certain conditions. But if you want to know the difference between 7.8 and 8.0, reliably, a calibrated pH meter is a better option.

It's also true that, if a pool's pH is out of range, the ABD test can allow you (well, us) to get a handle on whether 'this newbie pool' needs adjustment, or needs panic treatment to minimize damage.

But, I do wish that some of the tests -- and particularly that stinking Taylor manual -- came with a seal that said, "Open only under direction from PF mods or team members."