My reef has always struggled w/low pH due to a tightly sealed and poorly ventilated Florida home. Kalk helped some, running my skimmer airline outside helped some, dosing more Alk 24/7 as my corals grew helped some, but in the end I learned to stop obsessing and completely ignore pH (took me a while LOL).
With a calibrated Apex meter, for the last few years my Aquarium pH has been 7.65 at night and up to 7.9-8.0 during the day (higher in winter when we can open up the house). Here's a pic of my soon to be 5 year old tank-yours will be fine