Although he doesnt eat, does he show any response to food flying around him bro. If he does u still got chance. As the reefer upstairs said variety is key. I ever crushed my pellet slightly so that become even smaller pieces to entice my fish to eat before. Just not too much and the smaller pieces must fall near him. I got no experience with kole tang. Only yellow tang. But 1 lfs owner told me b4 that kole tang ship poorly so important to buy fish that is already eating and healthy and stable. At least more than half the battle won.