pH in fish tanks, I probably would encourage you to ignore this parameter completely for fishes.
Reef keepers (some of them) monitor pH and try to keep it nearer too 8, +/- 0.2 degrees BECAUSE coral may be better able to deposit calcium skeleton (and grow) at this target. Fish don't care, is my own summary, because I don't recall any normally running tank to have pH that impacted fishes health.
Fish people monitor nitrogen (nitrates) because it tends to accumulate in fish tanks as a result of metabolic activity. Keeping nitrates from accumuating by doing water changes in most systems is a method of ensuring good water quality for fishes. I don't think I have ever seen a link between pH and nitrate accumulation, but I post this hoping that other, better chemists and fish keepers will clarify this point if I am ignorant (too much?)
I have kept fishes for many years, pH ignored except for random, occasional testing because I have a pH test kit that was expiring or because I just calibrated the pH pen, but never did a pH result cause me to change water or worry about my fishes. Lots of words, I hope they are helpful to answer your question?
As mentioned above, I wouldn't worry about pH at all in general, but I'll add that if your tank is brand new, the pH will likely fluctuate at this time. If you really must check your pH, at least wait until your nitrogen cycle has completed