Okay, My kinda new CT betta named Percy is in a community tank and he loves it, that's not the problem tho, at night I have the tank light on before i go to sleep and he swims at the top back and forth flaring. I am not going to lie I think he is really pretty when he does it but I worry that it is bad for his health and maybe he is stressing or something. I have done some research and some people said it was bordem. I don't know! There isn't any female bettas or other colorful fish in their either.. Hmmmm..