hello, i have 6 flagtails total in 6 diffrent tanks, i have 3 - 6inchers in with pbass,dorado,aust. arrowana,odoe pike etc..., i have a 8 incher in with cichlids(cubans,bourcuti,pearsi etc...) and i have my big 12incher in with arrowana,temensis,pbass etc... so that might help you out good luck