800! Whoa. That's big and I'd love a picture or two when you get it going.
I've had Flames and Lemon Peels in 30, 40, 50 gallon tanks without issue. They were both pickers when it comes to coral. They really gave my LPS
a hard time. The occassional nip here and there doesn't seem like much, but it makes the coral retract often, which causes health problems for it over time.
I wouldn't trust one in a small reef, but a big one shouldn't be a big deal. I do love me a nice Flame or Lemon Peel Angel. Such great fish!