At one time I had a 125, a 50, a 55, a 30 tall and 2 15's to store feeders.
The 125 had 2 convicts (bad ass little fish) A Green Terror, Managuense, Red Devil, Shovel Nosed Catfish, Plecostamus, a Red Tail Shark, and a 2' Arowana. I had the Telapia Butterkoferi (A bad ass African Cichlid) in there but she beat the livin snot out of the Green Terror and started picking on the Arowana so I put her in the 30 tall by herself. She bit me twicw, the litte wench. The cichlids were all abot 8" long and the conivcts were pretty large 4" maybe. The Shovel nose was about a foot as was the Plecto. I had to put 25 feeders in that tank about 3 times a week so they wouldnt eat each other. The Red Devil and the Managuense mated twice. But the Plecto ate the row both times. Those would have been some funky fish.
Oh yeah...in the wild most of these fish would rule the Pirahna. They are kinda wimpy when they aren't feeding.
The 50 and 55 had an assortment of stuff, Red tail sharks, African cichlids, Bala sharks, Angels, all kinds of swimmin critters. After a while it just got to wacko so I sold all my stuff except for on 55 that now is the home of Sydney the Bearded Dragon.