If you have a powerhead that keeps clicking every time it turns on, chances are it’s due to the propeller kicking out and hitting the pump’s shroud. While this noise is something you could live with, it can be incredibly annoying if you are trying to make your aquarium quieter. Fortunately, there’s a simple solution to this issue. If you take a small piece of air tubing and place it over the impeller shaft, every time the pump turns on, the prop won’t make the clicking noise. At the very least, the noise will be significantly reduced.