Tank dimensions VS Tank capacity for tangs

[Gotem86]

First, I  apologize if a thread for this already exists. In fact, I bet there is multiple threads for this...

 

Anyways, I  understand that tang tank requirements are usually around 180 gallons. Is that actually true, or is tank length what really matters? I'm leaning towards length being far more important here. With that in mind, what kind of length is needed, 48", 60", 72", more? 

 

I'm interested in acquiring a tank that is 60x24x24  (150 gallons) and am thinking about possible stocking. I am trying to plan based on maximum fish size and don't care about "you can keep the fish for a couple years before needing to re-home it". 

 

Thanks in advance for your input.

[Humblefish]

It depends upon the genus. Acanthurus (e.g. Achilles, Powder Blue) really need swimming space to mitigate aggression. Zebrasoma (e.g. Yellow, Purple) and Ctenochaetus (e.g. Kole) are sometimes fine in just a 4-foot aquarium. But most tangs are still going to show aggression to any newcomers, especially other tangs. Which is why it is best to add all your tangs at the same time.