Ooohh i see i see... Well, the non-dominant one is 'suffering' from a spine ailment/tumor that's why I got worried about the bullying. So far he's okay, his damaged fin (which I'm not sure if due to bullying) somewhat healed a bit. I feel like the bullying is also contributing to his 'deterioration'. I could have separated them but I don't want to put anyone of them in a 10g. It's not 'that' bad actually. Should I do something about the bullying right now? Or just observe some more and like LeoKhomutov has said, make sure enough tanksize, hiding spot, and food (well that's another story, the non-dominant is not able to eat well probably due to that spine problem). Thanks!