Interesting, I have a 60 cube, and we added an ORA Mandarin in the first week of October. We saw him eat at the LFS (frozen mysis) so that was the deal sealer. My tank has been running since march, and was started with old mature rock, sand, and everything else.
We brought him home, and he immediately hunted for pods. I feed the tank on an almost daily basis with frozen mysis, bloodworms, and rod's, all in one cocktail. The first couple of weeks he was uninterested and food would sit in front on his face to no avail. Then one day, he started eating mysis. Some time later, he ate bloodworms as well, then rod's and now he devours everything. I even caught him taking the flight into the water column and competing for food with my saddleback! He hunts constantly, and eats frozen daily. He is looking fat, happy, and growing. His colors are getting more vivid and all seems well.
So far so good...... I'm hoping for the best, he is my favorite fish.