Newbie here! I have a 30K gallon pool with 2 skimmers. Lately, the pump has been louder than normal but not the screaming that bad bearings make (actually had these replaced just a few months ago). I ended up looking in the skimmers (have 2) and found two pvc lines at the bottom of each skimmer. One in each clearly has suction and these seem to be working just fine. However, the line appears to do nothing and it looks like one is clogged. I can feel debris in the line and with the pump off, if I try to clear the line, it clouds the water in the skimmer. What is this 2nd line for? How should I unclog it?