I've got a flame hawk that seems to pace back and forth around the top of the tank. It's starting to drive me crazy. I can tell when it's stressed because its color fades and gets lines in the black across the top of its back. I put it in a 10 gallon quarantine for a few days and it settled down. Back in the DT, and back to pacing. Been like this for months. Tank mates: yellow tang, two grammas, pink streaked wrasse, possum wrasse, two bangaii's, roland's damsel, and yellow goby. None of the fish really pay attention to the hawk, and none of the other fish act strange. Eats ok and looks healthy when perched. It's bright red from time to time during the day when it's not pacing. Tank is approximately 4 x 2 x 2 feet (29" wide) with lots of rock. Any ideas?