So what do you have in there now? the plecos babies will end up getting eaten if not hiden well. we have watched our aro pick off half growen clownloaches he grew up with.. as u can imagen we wernt very happy about it.
I think if u can get a nice knife fish, a clown or a royal it would look very nice in the tank. u wil just need to make sure nuthing is sharp so it does not get scrached and you will probaly have to hand feed( target feed it) so the aro does not eat it all.
Or u could go with a bornio tiger. such beautiful fish, remids me of a little puppy that follows us for food