I woke up today to find my male betta floating up near the top of the tank. Part of his body is a little above the water. He seems a little sluggish but he still swims in bursts. He seems to be having issues staying down under the surface. He's just swimming directly under the surface. When he dives, he just kind of bobs up. He doesn't look bloated or anything although I think he might have a mild case of fin rot.
My wife changed his water yesterday so I believe the amonia levels should be okay.
He doesn't appear to be having any problems breathing. His gills aren't moving fast.
Any idea as to what's going on or could he just like hanging at the surface?