55 galllon is a definite heaven for them! Except is you get just 20, then you won't notice them because they are small! I have 10 in my 29 gallon and it looks like they don't even exist! (exaggeration, but you know what i mean)
yes, these guys are great !!! they are small and mine eat just fine, I just throw in flake food, and somtimes I give treats ofcorse.. I only have 6 in a 5 hex, but they do pretty great with shrimp !! I have seen them not bother tigers, minami, and red cherrys, not that they wouldent' ofcorse no shrimp is completly safe, but these guys are the ones to get with your shrimp if you just gotta have some fish !! wish I could do it, all broke for now... will be lurking' ..... if somthing comes up I have to have, uknow I will buy atleast 25 ~!!!!!!