I can personally tell you it won't work, having done just that in my early days of fishkeeping. One of my first fish was a silver aro that ended up somewhere between 24" and 30" (can't remember the exact measurent), whom I kept in my largest tank at the time, a 125 long. Poor thing was horribly cramped and because of this was incredibly skittish and freaked out at the drop of a hat. Eventually ended up battering itself to death on the lid/sides, I presume trying to make it's way to more spacious accommodations.
The aro grew to that size, from 6 inches, in less than 2 years. Only after keeping another one years later in a 220, did I realize the difference in the fishes temperament the extra space brings, and now I'd recommend at least 6'x24" for the first few years. MFK member Flagtail has had his adults lay eggs in a 220, so I'd say that's the minimum (and a bare tank to maximize space as well).