I had one otto and one Betta in a 10 gallon planted fully cycled tank. The other Otto died and got my Betta sick. And the one left seemed happier by himself. Where there were two Otto, one seemed stressed (clamped fins, not active). My Betta ignores him. I got 10 neon tetras today, acclimated over three hours. After I put them in, they kept following Otto. Otto first try to brush them off, chase the tetras out of his territory. After he found out he can't kick them out, Otto went into hiding from them. An hour later, otto's actively shoaling with tetras. Is that normal? Or are the tetras stressing Otto out? This is the most active I have seen out of Otto. He usually stick around one spot forever and moves around more after I turn off all the lights at night. But he's now swimming from one end of the tank to the other, and FAST! Wouldn't sit still for a second. The question is: Is Otto stressed and acting out or just very happy shoaling with tetras?