new to pools. filter will not prime. Looking down at my skimmer there are two lines, rear line is to filter (from online diagrams) forward line is to main drain. water line is well below skimmer (pool half empty). I fill the skimmer and the skimmer drains. The skimmer is not completly level, the water from the forward line emptys until dry, the rear line starys full of water. Fill up the skimmer again and it drains from the forward line. Any help is appreciated.