It should get close to full size I had one in a 30 gal many years ago and it was 6-8" size.Gorgeous color at fullsize and like oscars very good "pet" fish interactive and recognizes its owner.
definatley, just make your weekly water changes and keep feeding a mix of live and pellets. Mine grew to 10 in a 30G before I traded it away to friend for some red devil fry Which I also grew one to about 10" and a pair grew to 13 and 10 in the 55 together.