Your profile says you have a niger and a Huma in a 55 with the lion? This tank is way too small for these fish and the triggers are notorious for picking on lions. Just the lion will outgrow a 55 in a matter of months. This could be the source of your problem. Even if they are all very small, they grow quickly and even small triggers can attack the lions fins. IMO, these 3 fish just don't belong together. If you got the lion at a lfs; I'd suggest you try to return him and start thinking of a bigger tank for the triggers.
ps: are you really feeding your fish hamburger, or did I read it wrong?
ps2: Triggers and corals are a whole new problem.
Please don't think I'm being too critical; but if your profile is correct, you have gotten some very questionable (at best) advice and really need to do some serious research on what you want to keep.