I found Rhys just laying on the bottom of the tank not moving much. When I went to net him out he didn't even attempt to move away. I put him in a little container with low water since he wasn't swimming much. It has about .5-1" of water and he hasn't actually swum up to get air. He's laying on top of his head/side and is breathing really hard. :/
What could it be?
He was fine yesterday. Swimming normally. He ate his 3 pellets. Nothing has been changed in his tank.