I have Cal Spa with one filter near the pump and another full size filter near the skimmer. The filter near the skimmer is above the water line. I'm not sure how to get the air out of this top one. When I run the filter the filter chamber has suction so it just draws more air when I open the bleed valve. If I open the chamber and just try to fill it with hose water the water drains down into the skimmer. I called Cal Spas and (despite what their ads say) they don't support spas before 2000. Mine is a 1990 PS-3 8'x8'. When I run the jets I hear the pump occasionally starve for air and the jets go down.