I have an inground pool, two skimmers, an attached spa, a pentair pump and a sand filter. This is my first year opening the pool without professional help and I cannot get the Kreepy Krauly to work. I have tried several different combinations of open and closed valves, but nothing seems to work. Baskets are all clean and water is circulating well, there also seems to be good suction. My theory is that in each of the skimmers are 2 holes with a "swinging" metal guard to close one of them off, what are they for? Does one of the holes need to be blocked off and if so, which one? Also, under the skimmer closest to the house (on the side of the pool) is a hole that was plugged for the winter, we have removed the plug but cannot find a cap that is supposed to go there., thoughts?