DI68
Aquarium Advice Freak
If you want tangs, then don't do anything short of a 6foot tank. I have a 6ftx26"x26" and the tangs I have use every inch of the space. I'm planning to upgrade to an 8 foot in the next year once my new house is finished being built. Plus you don't realize it until you get it but a 30" deep tank and 30" front to back would really require enough room to get behind the tank. Could you imagine trying to reach the bottom near the back glass in that shape of tank?
The tank was massive and unfortunately not suitable - it couldn't even fit through my door I came back relieved. Will be happy with my current tank while I get the hang of it and am selling off my tangs, foxface and wrasse. Will go for nano suitable fish next time.