that is a very complicated question... so you dont want fish that look similar. two different types of fish with bars could fight but this also depends on the particular fish and how different the colouration is. for e.g a blue bared fish might not chase down a pink bared fish as much as it would another blue fish without bars. if that helps at all... I've kept demasoni with labs happily both types breeding happily. I've also had peacocks and yellow labs together fine. I've had cynotilapia afra with demasoni aswell again no problems.. well apart from obvious african cichlid aggression also had no casualties in that tank although they all went in together as juveniles and each fish had the choice of two hiding places per fish. in my experience and dont quote me on this because I'm no expert but alot of it comes down to trial and error.I mean what kind of cichlids I can keep with my current setup. Need some variety but something which is not overly aggressive. Things are going good so far in my tank and I don't want to have some major bully.