Oh, I understand how systems and livestock can be different in any case, however from researching as well as personal experiance should be considered....this is from Bob Fenners web site....
"" The majority of Centropyge angels make for suitable to great aquarium specimens; however there are a few notable exceptions. In my opinion the Colin's, bicolor, multi-barred, Herald's, the (true) Lemonpeel, midnight, Potter's, and venustus are on-average, less hardy by far than other dwarf angel species. At the opposite end of the spectrum, the coral beauty (except from the Philippines), flame, Japanese, pearl-scaled, and rusty dwarf and most of the smaller (dwarf-dwarf) angels (C. acanthops, C. argi, C. aurantonotus, C. fisheri, flavicauda, C. resplendens) are my favorites as being most hardy and adaptable to aquarium conditions. The "rest" of Centropyge species, , either lie somewhere between the worst and best rating or my personal and recorded experience is too limited to rank them high or low. ""
In regards to the Emperor....
"" For most hobbyists I strongly encourage the trial of individuals only starting between 10-14 cm. size. These seem best suited for beginning life in captive conditions. Larger one's have more difficulty adapting to aquariums and smaller one's don't accept prepared foods as well. There are, of course, exceptions, but this is my rule of thumb guideline. ""
BTW, congraulations on haveing some success with the Lemmonpeel but can you explain how long you had yours and why you speak of yours in the PAST tense....