My bala's sleep at a 45 degree angle, its kinda cool, if you sneak into the room at night after lights have been out for a few hours I can catch them sleeping. They float stationary in the middle of the tank, all grouped together at a 45 angle.
Side note how I catch fish in big tank. I use a big net that's wider then the tank, like you get for fishing. Then I do a water change, so now the water is lower then the net, and net is wider then the tank.