At the John C. Shedd Aquarium in Chicago they have in a the "Fishes of the World" tank the largest one easily over 1000+ gallons 3 Pirarucu's,4 Green/Black???Pacus (Huge! there Width are very impressive), like 4 RTC's, and two TSN over 3 feet. Plus large Plecos, Geos, and Doradids.