so i am planning on starting a 20 long reef tank. currently, i am planning my livestock. i really want a tang-LIKE fish (i.e. a somewhat large fish for my tank yk not an actual tang obiv). I've been looking at dwarf angels and I've been thinking abt the cherub angel. but a lot of people are saying that they are 50/50 when it comes to reefs or that 20 long is too small but others have said that the cherubs are peaceful and a 20 long is fine since it has the same footprint as a 30 i just need to have lots of rock etc. my current stocking as of now is one clown, a firefish, a lawnmower blenny/watchman goby, and maybe a possum wrassse/one Banggai cardinal. if i put a "/" than that means one or the other. I am not planning on exceeding 5 fish with 4 being my safe number. what do you guys think? i just want a somewhat large (as large fish i can have for a 20 long) fish that is colorful that will work in a 20 long (30 x 12 x 12 in). any suggestions? thanks!