There is a tube that rises from the bottom rack, it blows water up like a fountain, it does not touch the bottom of the 2nd rack sprayer, somehow it suppose to squirt water into the sprayer, and the ater comes out the holes in the arms. But what makes it rotate? Mine just stays in one spot, yet if I tap it it spins free enough. Am I missing a part? Shouldn't there be an impeller or something to guilde the water, and as well turn the arms? Other wise the water just blows up into, and through the arm, and bounces of the top of the inside of the dishwasher, the amount of water that comes out of the holes in the arm is plentiful, I hake cleaned thearms out with a wire, and there's is no clogs, but what should make it spin? It just sits there and does not move?