This isn't a fish that is often seen at maximum size in aquariums. It's such a PITA that owners tend to "re-home" them long before they can grow that large.
These guys tend to harass other fish mercilessly, sucking and rasping at their sides and damaging their slime coats. Some start this behaviour while still young and small, others develop it only when larger. I like the look of them and so have tried them numerous times with numerous species of tankmates, always ended badly sooner or later.
Currently I have a trio of Garra rufa, the so-called "doctor fish", in my community tank, and they are a great substitute for CAE. Similar look, same streamlined torpedo body, same high speed and high activity and...so far...no aggression at all. They are around 5 inches now and seem to have pretty much finished growing. I'd never buy another CAE.