Your lights-out pH is low enough to be of some concern, but not so low that it merits a concerted effort to change it. Your reef's health is the best barometer, and if corals seem healthy and colorful with some growth, it's not a problem.
Chasing pH with additives basically never works long-term, so if you do want to raise your pH in the future, your options are:
First, get a CO2 scrubber for your skimmer. CO2 leads to the formation of carbonic acid, which lowers your pH. Many homes are actually quite high in ambient CO2, so it's not at all unusual for a CO2 scrubber to make a noticeable difference.
Second, add a refugium or algae turf scrubber to your sump on a reverse photoperiod. Photosynthesis during your tank's normal "sleep" period will take CO2 out of the water and replace it with O2, raising the floor on your pH and allowing for higher pH levels.
Third, find other ways to increase coral photosynthesis. Increased daytime photosynthesis will increase your pH as well.
Fourth, find a way to pull in outside air (presumably higher in O2) to feed your protein skimmer. With less CO2 entering your water, your pH will naturally rise.
Having said all that, chasing pH is a fool's errand. It's not a direct parameter (like, for example, calcium), but rather the result of all the chemistry going on in your tank. There are tons of inputs that impact your pH level, and there are only a few that we can directly impact.
