[Tangs Rule]

You could run into a problem with 2 powder blue tangs and an achilles tang. If you are going that route, I would try 1 big and 2 smaller sized fish. Also, an Emperor Angel and Blue Ring angel are a recipe for disaster unless you get one as an adult and one as a juvenile. But when the juvenile grows into an adult, there could be a problem. 16 fish in a 280 gallon is a lot, but it can be done. Be sure you have a good protein skimmer, a good uv sterilizer and are willing to change at least 40 gallons every week to two weeks.