You know what, the tangs I had never cared much for Nori, and hanging it on clip usually ended up with big mess in the tank because it degrades fast. I'd try a nice very dark leafy rommaine lettuce leaf. Never seen a tang turn that down, once they figured out that that werid thing hanging in the current was food. Yes, seaweed is the preferred food, but at this point, just getting the tang to nip at something would be good. My tangs got pretty dang plump on rommaine.