Hi. Feed the BTA small pieces of shrimp (krill), squid pieces, or silversides. As for the tang, they sometimes have to be taught to eat nori. Usually takes them a few days to catch on, although they can also learn from other fish. I would dose the nori (seaweed) with garlic extract to entice it to eat. Or just crumble a bit into small pieces in the water column. He'll catch on eventually.