This autohumidity pump "thingy" was tricky. The photo is poor, but there's a tube that's wrapped around a rotating head on the top. It's black. I had to double the tube around the pump to make the tube taught. I discovered the tube must be taught in order to draw water from the reservoir below. So as the head rotates, it "grabs' water inside the tube and sends it down the line. Has anyone else had trouble with this pump?