go to a fish store and get some good food, different kinds. But for a tang you should always have algae as part of his diet. I've read too many conflicting ideas on including human veggies as part of the diet, but definitely get him some spirulina flakes and some seaweed sheets. Also Zoe is a very good additive for all fish foods. My Yellow Tang eats every thing, but I do notice he nips at the rocks and algea when I haven't fed in a while. On days I'm home all day, I like to feed in small increments, and he won't touch the rocks. But I rarely don't include spirulina in my mix. He hangs with my 2 percs in the middle of the tank, just waiting:jumping: . As far as the injury, that is definitely one nasty hicky. I would have been proud of that in 10th grade:cheer: . Hopefully it won't be to bad, and he'll recover. As with any bruise, he's had an injury to his muscles (at least that's what a human bruise is), and he may not act normally for awhile...don't do anything to stress him out in the next few days would be my advice.......HTH