Take water from below the water surface by attaching the bulkhead fitting to the flat front of your Savio Skimmerfilter. The PVC flex pipe extends to the pond where it is attached to (and through) the pond liner through a second bulkhead fitting. Part shown has a piece of liner attached for demonstration only. This fitting is helpful if the water goes below the weir opening of the skimmer because it keeps water in the skimmer so the pump doesn’t run dry. This fitting also helps take water from deeper in the pond rather than just from the surface.