I have two 6040’s one is about two years old the other I purchased last November. When the original pump is set to 100% there is significant flow from the pump and the flow can be felt when I place my hand about a foot in front of it. The newer pump is putting out significantly less flow with the same settings. I place my hand in front of it at the same distance and feel about a quarter of the flow I feel from the older pump. Everything looks identical between the pumps, same power supply, blue disk is present in both, and they are both clean. Any ideas?