Ok I have a salvini and a rd in a tank together and they are both at 3" or so. The aggression has come out in the rd a little bit but it likes to go after The salvini. They had a pretty good liplocking battle that I got on video. I like the salvini and its colors and I also like The rds. It it worth trying to keep The two together because I'm not sure if the salvini is going to be able to keep up with the rd. Don't get me wrong the salvini definitely held its own but I have seen some brutal rds. Anyone kept salvini and know more about there aggression?