I've had my betta, Cujo, for about 2 weeks. He is in a planted 10 gallon tank with 2 ghost shrimp, 3 juli cory cats, and and apple snail. They all get along and actually play together a lot lol. Well, whenever I turn off my bedroom lights, Cujo puffs up at the reflection in the glass, because the light in the tank is still on. He continues to fight his reflection until I turn the lights o again. Is this bad for him? If it is a problem, what can I do about it? I'd rather not have to leave my room light on after dark just to keep him from fighting himself. Thanks for all of the help everyone. :)

hahahaaha, Hi :)

Omg, whenever MY lights are off and TANK lights are on he will flare. I think with the lights off they see their refleciton. Simple answer when your sleeping, turn off the tank light and your light. You will notice he will no longer see his reflection and rest. Email me with you questions/concerns.

It is good to "exercise" your betta once and a while, but when they flare it takes up a lot of energy, which can stress them out if they do it for a long time. It's not that big of a problem, but if you do see him doing it for too long maybe you can put a little lamp or night light beside the tank. Maybe this will get rid of the reflection?? Or you could compromise, you know, turn your lights off later and turn your tank light off earlier. Fish need at least 16 hours of dark anyways. But really, it's not that much to worry about