First and formost, i would like to extend my apologies to those that were kind enough to render advice when i need and in return been absolutely pissed. Anyway, wats done cannot be undone. I have released the Purple Tang into the main tank. After a short squabble, both Tangs are swimming and feeding alongside without signs of stress nor aggression. I feed them a good variety of frozen and live food including red seaweed by two little fishes. Hope you guys are happy for me. Other than returning the Tangs to the shop, i welcome any further advice to make the Tangs as healthy as posible.