I have a 24ft above ground pool. I am adding an in wall skimmer and I want to know is that sufficient suction? Or should I also I use one of the existing suction ports as well? The pool has 2 and I wondered if I should plug both of them or just one once I add my skimmer? Next question I want to add a 2nd return line but where? Shoud it be close to the skimmer or opposite side?