I've searched through this site but haven't found anything that is specific to this problem. Pool is open, no bubbles appearing in pool that indicates air is being sucked through the lines But...the suction at the skimmer is so low that I don't even try to vacuum through this connection. (Thank goodness I have both a polaris and a robot vac!) We've checked all the plugs at the pump and pump skimmer, at the filter, and at the polaris. All seem to be tight and not leaking. Any ideas as to what is causing the poor suction? This is an inground gunnite 30k gallon pool.