I've had one that was 6" without the fins...he was a bruiser....he female was 4"....they were freakin rabbits! *grrr*....they grew up pretty fast too cuz they were kept in the 300 gal as dithers! lol....i dunno how fast the fry gro though....whenever i got them i would grow them to a certain size and then feed them to my fish...hehehe...they served their cause. They grow about the same as any other cichlid...nothing special. Want a fish that grows fast get pike cichlids, oscars, or pbass...some of the fastest growin cichlids right there...