Hello all I recently bought a house with a pool and am attempting to close on my own because of the rediculous cost of paying someone. My issue is in trying to blow the lines out. Every thing I read and watch says to put an air compressor or shop vac in the skimmer and the line will blow out. When I do it however the air goes directly to the filter and it does nothing to any of the returns. I lowered the water and was able to clear the side return lines however I'm stuck on the floor return in the 6' deep end. I've turned every valve and not even a bubble. Unfortunately there was nothing left by the previous owner to explain what any of the valves or ones go to. Any help would be much appreciated.