My pH is at 7.84 right now and rarely exceeds 8.0 during the winter. The problem is CO2 buildup in your (and mine) aquarium/house that pushes the pH down. Think of it as ocean acidification on a small scale. Your alkalinity is already in the high range of acceptable so I would be careful that you do not raise it much higher with Reef Buffer. That product won't work very well as a long term solution so this article has some more ideas:
Low pH: Causes and Cures
http://reefkeeping.com/issues/2004-09/rhf/index.htm
However I wouldn't worry too much about it unless you're running a Calcium Reactor or your pH drops even lower.