betta stress

Hello, I have a crowntail betta. Ive had him for almost a month now. Hes usually very active and a bit of an eater. I have been away for a few days (my brother fed him while i was away). i noticed he stayed at the bottom of the tank a lot today which isnt his norm. Hes normally a happy little...

I've had a betta in a 20 gallon for about two months now and I figured 20 gallons is pretty big for one betta so I divided the tank and added another betta to the other side. The divider is a black plastic mesh like material and I have it double layered to make it a little harder to see through...