It's been done before, here's one with the same tank (210gal);
http://www.youtube.com/user/Mezico#p/u/34/Gp93_c3Ioa4
The main problem that guy (he's a member on another forum) ran into, was bioload. With a multitude of hungry, meaty-eating mouths to feed, keeping the water parameters even reasonable wasa losing battle. The triggers are just going to continue to grow, and make the situation worse, then it already is. As you can see in the vid, algae is there, and the algae just got worse. He slowly got rid of the triggers and went in a different direction.
Triggers (and their distant cousins, Puffers) usually represent the heaviest fish in terms of bioload in an aquarium. Messy eaters with a lot of food that goes to waste, and not being able to have inverts that help, only make it worse. Perhaps 2 triggers with other fish species, may be a better path.
