I have a 22 x 52 pool. I just set it up. So for now I am using the pump that came with it. However I have installed a bottom drain in the center of the pool and sidewall skimmer on it and capped them both in preparation for a pump/filter upgrade. I was given a hayward t220 filter (52GPM recommended), and I'm looking for a pump to fit it. I've been looking on Amazon to see what similar filters are paired with and all of them that size are coming with a 1.5hp matrix pump sp1593 . According to my calculations that pump is way to big for that filter am I correct. By my calculations I can get a sp1591 and it will still be to big for that filter with my head pressure. My bottom drain is 30 ft from my pump location and my skimmer is 28 ft. So based on my pool holding about 10,500 gallons and my head pressure being about 27 and I plan on turning over my pool once every four hrs I calculate I need something smaller than a sp1591. Am I wrong or missing something here? What size pump should I use with this setup? I was also looking to get a two speed matrix pump, to run on low primarily and on high when vacuuming and etc. I have a lot of tree in my yard as well as a lot of birds if that makes a difference.