Check your water co's web-site . . . should/may contain area pH of drinking water?
EVERY method I've tried in pH testing, including two pricey digital meters, ALL show different #'s.
The test tube type #'s didn't mesh at all w/the "official" digital reading(s). It's a bit of a crap shoot, IMO.
As long as plants are growing and apparently happy/healthy, I no longer worry about pH.