Are you dosing anything to raise your Ph?
7.8-8.5 Ph is what most reefers run, you aren't that far off. You could start off by doing a large water change. Is your salt mix higher in Ph?
Are you sure it's your Ph?
What are you other parameters?
How old is the tank?
Unless you are taking active measures to raise pH, then that value is likely not accurate. Simple aeration will lower it if it is real. I do not think it will hurt corals.