I have 2 oscars in mine as well and 2 blood parrots and a bichir that is about a foot long none of them have bothered them. I mean they make there way over to that side if the tank but the parents run them off. Now that my fry has gotten a lot larger and there starting to show stripes they have gotten a lot braver moving about the tank. Even some of the babies have started showing some dominance when they are in what I call their rock structures. It's the funniest thing watching them push the other fish out.