I kept a tomini for some time and found him to be a great fish, kinda like a more passive zebrasoma. All he did was calmly cruise about the rock work all day snacking, and didn't ever bother anybody. Unfortunately I lost him in a marine velvet outbreak set off by a purple tang :headway: I'd say a 55g is the minimum I'd put your typical bristle tooth in, chevrons have the largest max size as far as I know, so I'd say a 75g for them, as long as it's 4' long. Like zebrasoma, bristletooths are better suited to captivity than other genera because they have slow growth rates, and are much more "stationary", meaning they seem to be more content exploring the rockwork, feeding all day, than pacing the length of the tank. They also don't seem to be nearly as prone to disease IME. Good luck :beer: