I currently have a 180 Gallon Reef Tank. The Current Population Includes 1 Blue Hippo Tang (Dory). I will (within the next month) rehome 2 clown Fish and a small starry blennie to the 180. The other occupants a 6 line wrasse, 3 small Chromis. Is it to much to add another tang (is is to late? the Tang has been in the tank for about a year (There used to be a blond naso, but he died about 9 months ago or so.)