Basically, CYA tested *higher* after a night of very significant rain (several inches) Other than salt, no other parameters were significantly changed. Salt decreased several hundred ppm (3300 to 2650) and CH went down from 280 to 250. Those changes all make sense to me which is why I tested this morning after the rains were over.
What doesn't make sense is CYA tested higher by 15ppm. The inky explanation I can think of for that is operator error, although I've did the test the same way as always (it's subjective but not difficult to perform).