If your pH is actually that high (and that's way up there), you might be better served just buying spring water from the grocery store. With a 2.5 gallon tank, it wouldn't be too expensive to do water changes.
In my experience, adding buffers and pH adjusters is just a means of killing fish, because of the rapid pH fluctuations it causes.
edit: I just noticed your location is Boston, MA. Is there actually any place in Boston with tap pH values that high?