Of course the bigger the better, but I have kept singles in a 55 a small pair would be okay in a 75 for a while. These sizes would not be considered ideal, but possible, with good water quality. These fish do get large although kind of slowly compared to other cichlids. My largest pair is in a 220 and the male is about 13 inches female is about 10 inches.They're awesome. What do you consider the min tank size?