Let me start out with saying that the Achilles Tang is probably my favorite Reef Fish BUT................. IME,IMO the VERY WORST to CONFINE in any Aquarium less than say 20,000 gallons like Bill Wans ??? I would conservatively say that 80% DIE in captivity, most within the first several days. I have worked in this industry for many years on the retail end have also had the pleasure to collect while in Hawaii. If any has seen these in the wild they would know just how unreasonable it is to think we can/should keep them in glass cages. A pair will defend and guard against most any intruder a territory larger than most major Public Aquariums main displays. I've seen them take on a school of Spinner Dolphins maybe 200+ strong and while walking the cliffs of Hawaii you can look down and get a great perspective to how large their territory is 50,000.... 100,000 gallons ???? There are always exceptions to the rule but as a whole these beautiful fish are ultra high strung animals that belong only in the wild. Hope you and any other keeping them the best of luck but please don't perpetuate the myth that it is an acceptable fish for our Reeftanks. NO APOLOGIES here, I take this one very seriously.
Cheers, Todd