I need to purchase a new pump and am not sure where to start. I have a 24x54in round above ground pool with sand filter. Is 1hp good? 1.5 hp? From what i have read its borderline? 1speed or 2speed. What is the best brand? I live in NC and the swim season is long and summers are HOT. (not sure if that has anything to do with it or not but just in case) Thank you, as always