If your growing that many you must have a certain way of dealing the killings.
Space, bro.
But they do kill eachother every now and again. some have been killed, yes, but not many. I quit raising flowerhorn fry bc of the killing, I was loosing tons of money and potential not putting them in cells from birth. But these guys don't seem to mind so much. They are short body red texas though, which I like (among other reasons) because they don't need as much space or "run" as fast as the regular carpintis breeds, which I find rather skittish in aquariums.