I have noticed that I have a fairly steady stream of sap (very small stream but steady) from my dry line. The amount is small compared to my wet line. I am wondering if anyone can tell me what would cause this? Is it an indication that my system is so tight that the dry line is actually sucking sap up to it from the wet line below it? What would cause this and how do I fix it (More boosters? Introduce some air? ) or is it nothing to be concerned about? This is my first year with vacuum so learning as I go.