So I bought a house last year with an above ground pool, my first pool to maintain. It has a skimmer and a filter or drain "not exactly sure what to call it" cut in in the bottom center of the lining. Both the skimmer and this bottom drain currently run into a Hayward 4 way ball valve SP0735 then into the filter. it's cracked and slowly leaking. I plan on replacing before opening the pool. I was doing a little research and it seems that this valve is more used for backwash the filter. Anyone have recommendations for a valve to replace it with and then come winter time how do I empty this bottom drain without draining pool to prevent freezing