One of the things I would say an Achilles needs is lots of room compared to the average tang (only speaking from others experiences though) as they tend to be much more active than an average tang.
Whenever I have gone to Brads (untamed) place to see his 400G, the Achilles is always the most active fish in that thing!
Size isn't always everything
He may be smaller than a Naso for example but I would argue he needs a bigger home just because of their behavior.
Most reputable sites and a few threads I have read about them on RC have one thing in common and its the large tank requirement to keep them stress free and therefore ich free...but I know a few people are going to jump all over what I am saying and want proof and others will argue about how theirs is doing fine in whatever sized tank. This is just generally what I have heard makes them so tough to keep.
After trying a Powder Brown for the first time a month back, I would say it was about the same thing...I even felt he was a bit much for my 200G because of how active he was
Good luck!
With the tang and this thread
