Yes, you need two pumps to fly sparge on a single tier stand. I batch sparge on mine. If you underlet your sparge water, you are going to disturb the grain bed. But if you stir your mash for batch sparging anyway, that shouldn't matter much. I have a top port on my MLT with an adjustable return that I place just below the mash bed. I recirculate with the pump, and the return creates a bit of a stirring/whirlpool that seems to mix things up without really disturbing the bed. With a bazooka screen like I had on my cooler MLT, disturbing the bed wasn't as big of a deal. But with the false bottom, I'm less inclined to stir things up. Seems more prone to channeling. On the other hand, the pump doesn't seem to cause it to compact or stick too easily.