carefull tangs need alot of food which means nitrates which mean water changes till you establish a balance of natural uptake by bacteria and corals and your own water change schedule.
i have a 300 with total water volume of 550 now and definitely see alot of skillet from the tangs being feed all the time to keep them healthy. honeslty ten chromis fill the tank better fast and balance better plus are cheap. tang can go in any time mostly. and buying them smaller saves money as they will grow with the systems demands .
GL keep us posted. Top shelf and sea in the city have been my best sources for fish lately. they take good care of the club members if you take your card.

over all as a whole i have had poor success with fish this year. but corals have been great.