I am aware of the toxin thay excrete if they die or get really stressed out. I'm sure it will take him awhile to get huge. He's in a peaceful tank so he dosent stress out. He pretty much eats what ever food I put in the tank-he needs to have his "greens" though. He eats krill, frozen brine shrimp cubes and flake food. My humu humu and my boxfish eat off of the same cube of frozen food that I put in there. They're both about the same size.