Well,i have 4 atabapo in the setup and 6 psittacus.The other 2 ats are hiding but are allowed to come out in feeding time,They are wonderful fishes and are the bosses of the setup.A little fighting with the psittacus but not so very mean,i was on a long journey some weeks and coming home the fifth at. was found dead. They were only feed every 4 day when i was away.Have a lot of hiding places and i think they can not go with fishes that dont take back.They are very greedy ,just like an oscar,so i am carefully so they dont get choked.i am impressed what they can fill in their mouths.Water change 70% a week.Had 4 saxatilis whith them,that are gone now,so they are not so easy,powerfull predators,and they are wild caught.Filtration is one eheim 2260 and one 2028.The aguarium is 125 gallon.