I feel kinda dumb for asking that question, now. Lol. There isn't any current on the surface at all, on his side, at least. He's furthest away from the filter since he is also not that great a swimmer for some reason. Probably either his long tail or his weird ventrals. But anyway, yeahhhh.... I also wouldn't be surprised to learn he's just a weirdo like that. Lol. Thanks, 1fish2fish.
“Everybody is a genius. But if you judge a fish by its ability to climb a tree, it will live its whole life believing that it is stupid.” - Albert Einstein