Beautiful fish, but like all angelfish, may or may not decide to develop a taste for corals. Here's what Bob Fenner has to say:
http://www.wetwebmedia.com/pottersangel.htm
"Historically the Potter's angel has a lousy survival record in captivity. Likely less than five percent are alive within one month of capture... Most of this attrition can be traced to damage in collection (getting thrashed by nets, their gill/opercular spine getting caught in netting), holding (totally unnatural "cubicle" settings or mixed in with fishes w/ no cover to hide in), shipping in too small bags... Along with dealers' and hobbyists' practiced ignorance in keeping the species in inappropriate settings.
This species needs room (at least a hundred gallons), with lots of spaces, crevices to dart through and out of the way, and a paucity of too-active fishes kept with it. The best situation, as you might also assume, would be a biotopic Hawaiian reef slope set-up with species to be found there.
Given plenty of healthy live rock and a calm, stable setting of size, and of course the selection of an initially healthy specimen, the Potter's is not a difficult animal to keep. "