I don't quite understand why everybody seems to carry the whole "its a triggerfish, itll go crazy one day" mentality. I've had 3 Nigers, 2 Picassos, and a bursa. they all were in the tank with either the Black volitan I had, or the fuzzy dwarf. the only time I experienced a broken spine was with my black volitan and I was trying to feed him and he overshot. the one thing that I would def stay on top of is keeping their bellies full, this will alleviate a lot of their aggressive tendencies, especially if they don't feel the need to compete for food. although im heading in a different direction now with my tank, I must say it was nice to have the fish that most salties couldn't have. plus anytime I had a fish casuality in my house, someone in the aggressive tank would eat it lol