I got a new group of 5 head and tail tetras today but one seem to have a big bite wound on his back, he hasn't got a ddorsal fin, it looks kinda old and its not at all fin rot non of the other fish are infected with it it was just this one. Will his fin heal? He's swimming and eating fine hehe his "lights" are on, and swimming with the rest of the fish. He'll survive won't he? lol I'm more worried about the "lost" one who isnt swimming with the shoal at all he thinks he's a guppy fry lol.