Mystery in my 300 gal

[PhantomHalo]

So, I have fish that keep disappearing in my 300 gal. It is full of GHA that I am trying to get to the bottom of, but tonight it is hitting me after spotting one of my tangs (Kole tang) are missing. He, along with a Lubbock wrasse, tail spot blenny, small chromis, 1x clownfish, have all disappeared. My magnificent fox face died due to being bullied by the triggers and my powder brown tang after only 3 days. The list of suspects are a blue jaw trigger, black trigger, pink tail trigger, or a baseball size BTA. All of which are in the 5-6” range. The tank has a canopy with a screen in the back to catch most jumpers. (They could get lucky in the corners and make it through, but not likely.) The overflows have a foam top so nothing can get in from above. So the question is, where are they going? Triggers actually eating them or do you think they are dying off and are stuck behind the rock work somewhere? It’s a pretty open concept tank, but I can’t see behind the center rock work pile. Does anyone have any experience with these triggers eating other fish? The tank was about 1/2-3/4 their size. Thanks for the help!

 

[Big G]

Any crabs in the tank?

 

[PhantomHalo]

Only small hermits that have survived staying clear of the triggers.