Unless im mistaken and maybe I am, jack dempseys grow to 8-9" max from everything Iv read about them. Green terrors 8-9 in aquariums , severum about 10.
Sent from my iPhone using MonsterAquariaNetwork app
Anyway, males usually top out at about 8-9 inches. 11-12 inches is very uncommon. I think a male or a female would work.Female JDs don't get as big as the males..