@Mitch... .. I have read that several is better than a few. I have 5. Was supposed to be 6 but someone did not check the bag before she threw it away.:frustrat:
Anyway, they are pretty snarky with each other. There is definitely an odd man out in this group ... wishin' I had the 6th guy. The 5th is smaller & blotchy. The blotchyness comes and goes, so maybe he will last but it has become the runt. The others almost dance with each other. They flitter around protrusions on the rock several times ... like a dance. Sometimes there are 2, sometimes 1 by itself. I recently saw 1 doing this by itself around some algae on the back wall. Might have been saying, "Jeff, clean this cr@p!". Not sure that was the message, but the back wall is now clean.
They are related to damsels and clown fish. So the aggression as they get larger is in character. I will say 5 is the bottom limit and that is with plenty of live rock stacked for lots of hiding places.