well, first of all if the only reason that you r intersted in getting into p's is because u want a mean agressive fish your expectations probably will not be met. each fish is different. i have had three irritans and one out of the three was the most skittish, scared, and least interactive fish that i have ever had. althouhg my other two irritans will try to bite me through the glass. if u want fish taht are active (this is why i have a pygo shoal) i would get 3 rbp that r small and they will be fine in a 55 for a while. if u want a single p i would get an irritan. it can stay in a 55 for life and if u r lucky u will get a active, aggressive one. if you r looking for massive attacks wiht fish getting torn to pieces u probably will be dissapointed. your fish will probably not move or eat for a couple of weeks after u getting them and maybe a month. get a p ror the right reasons not just to watch them tear up fish. if you have any questions pm me. welcome to the site there is a ton of information and great people on this site