I just got rid of one I got at 2", but it grew FAST and ate like a mad man. They are mean as hell. once mine hit 10", about 4 mnths or so, he started attacking my fh and devil. when id wake in the morning, they would all have bite marks and shredded fins. was doing a water change and he took a good dime to nickle sized chunk out of the middle of my thumb and index finger. OUCH. never got bit by my old RBP's, but after keeping that cat, watch your fingers. No joke, they will attack and can take flesh. other than that, the red started to come on to the tail around 8". pretty fish, mean as hell.