PH Issue?

Your water sounds like mine. I get the bright 7.6 blue with the standard tester and 7.4 with the high range.

The standard one jumps from 7.2 to 7.6 on the shade card so that bright blue could mean exactly 7.6 or just nearer 7.6 than 7.2.
Similarly, high range jumps from 7.4 to 7.8 on the shade card so a 7.4 colour might well mean nearer 7.4 than 7.8.

I count my pH as being about 7.5, ie in the overlap between the two testers.




Incidentally, my freshly run tapwater shows greener than 7.6 but bluer than 7.2. It is typical that freshly run tapwater is lower than tank water or tapwater that has been allowed to stand for 24 hours.