JoeDizzleMPLS;2103740; said:they aren't a typical shoaling fish, the numbers thing is kind of a myth when it comes to piranhas. alot of people say that you shouldn't have two because the dominant one will be aggressive towards the other one or prevent it from eating, but that's not the case with every pair. one fish can be just as comfortable by itself as it would be in a group, they are however usually a bit more entertaining in a group due to the fact that there is competition for food
I agree I kept 2 RBPs in a 55 for a couple of months and they did just fine. They got along just great, there was no fin nipping at all. I upgraded to a bigger tank and added 3 more RBP and I would say they fight more often now.
