New Naso Tang

Well, I thought things were looking up. The tang was starting to graze the rocks throughout the day, and it began to eat nori. Although for some reason it doesn't seem to show any difference in appetite when I soak the nori in garlic. It would just casually take a bite here and there. But then this morning I turned on the lights and it came right out and ate a couple formula 2 pellets, and then went into his hiding spot and got right up against a rock and hes been there, damn near still for almost an hour now. Scaring me a little!! Any thoughts/ideas??