If it makes ya feel any better my well water goes from 6.5 out of the tap to about 8.0 once degassed.
Do you have KH and GH tests by chance? I would check these and be more concerned with that then PH unless you do find out its the sand causing it.
I have to use a GH booster for mine since its about 1 drop out of the well. What I maintain in both tanks is KH-4, GH-4 or 5, PH 8. My RCS and cories are always making babies and pretty sure my CPDs are giving it a shot as well. I also have ember tetras, OTOs, Nerites which are doing good and seem healthy.