Dealing with a predator in a reef

[AngryTriGGer]

Not too sure exactly how I should deal with this as I'm somewhat new to marine tank keeping, (with in the last year and a half.) I've recently lost 3 fish, Mandarin dragonet, Lawnmower blenny, and now my Firefish. I'm pretty sure it's a predator of some sort as I have been hearing a clicking in my tank, usually after the lights go out. I have a 46 bow with about 60lbs of rock. I also have a 55 fowlr with a Dragon wrasse, Picasso trigger, Valentini all about 2-2 1/2". I also just got a 5" Niger trigger from a bud. Yes I know the 55 is too small as these fish are going to get big and I plan on upgrading. The Niger was in a 33 but thats a whole other story, and I figure I'm doing him a favour by giving him an extra foot of swimming room for now. Anyhow I'm wondering if I removed the rock work from my reef, as I'm unable to pin point which rock this predator may be in, and placed it in my fowlr, would my predators do the work on the predator living in my reef rock? I do know by doing so I will more than likely lose all my brittle stars, speghetti worms, etc. but I'm willing to do this in order to save my fish. Thanks for your time.