There's nothing wrong with
a pH of 8 to 8.5.

I've heard that high pH values aren't bad for fish, but I read that
plants have a difficult time absorbing nurtients with a pH above 7.8 -
especially the free floating ones. My Hyacinths are looking pretty
sad and from what I read a high pH will cause the symptoms that I have
seen with them.

Maybe I am being a little too worried over this. The fish seem happy
and the rooted aquatic plants are growing, since I live in Florida I
will always have easy access to water hyacinths anytime I want them so
maybe I should hold off on playing with the pH for a few more weeks.