I've had a 4-5 inch Powder Brown Tang in my 125 for almost a week now, it's the only tang, and largest fish in the tank. It appears happy and healthy, but it literally will not eat. I've tried frozen LRS Fish Frenzy, three different freeze dried foods, two different pellet foods, and nori sheets. All the other fish are eating everything, but this PBT just completely ignores all food every time I feed the tank. He swims all over, doesn't bother any other fish, goes in and out of rocks, but just refuses to eat. What can I do to get this guy to eat?! It has to be starving at this point.