If it has been about a week since you added any stabilizer (CYA) so that you know it has all dissolved, then I'd add a little more to bump you up to about 40.

is 7.8 the highest reading that your pH tester can differentiate? If so, was your 7.8 a true 7.8 or was it actually even a darker red than that?

By the way, a BIG, BIG, thank you for becoming a lifetime member! That is SO awesome and we really appreciate it very much! Ben was very pleased to see that you had done so. We are very happy to have you be a part of our forum!