So I went to do a WC on my 24G tonight, and didn't see my angel. After looking for a few minutes I found him, flat on the substrate mixed in with some plants. I THINK he was trapped, though I can't see how. While the pump flow is above where he was, it blows away, so it would have had to go all the way around the tank to get there and trap him. I doubt that happened. Thinking he was dead, I went to fish him out with the net. Once I tapped him with it he flinched, I prodded him out, and he went on his way. I've seen him swim at odd angles before, even sideways to fit through a hole in decor, but never actually lie on the ground motionless. He seems all right now, and we'll see what happens when I feed in 6 hours or so, but should I be concerned at all?