HELP! Old tang not friendly with new tang

[bryceschutte]

So I added a new tang today and my other tang really didn't like it. TO the point of doing the tail whip thing and cutting the new tang open. I promptly moved the new tang to the sump. I moved some rock around and tossed some pellets in the tank but that did not stop the mean tang. ANy other suggestions?

I have added other fish and even other tangs with no problems.

The only thing I can think of is the new tang is smaller than the other tang and any other tangs that I have added previously.

Also the new tang I added is fairly sickly looking. Skinny, nipped at fins, and not very yellow. I dont know if any of this applies but more info the better I figure.

ON a possitive note as I was moving my rock around I found a mushroom that I never knew i had