Well, I looking at a 27' round pool (54" wall) Local store uses a pump with 1.5" plumbing and is a 2 speed pump, assuming 1.5hp (i"ll need to check on that), and was atleast a 24" sand filter(i think he said it was slightly bigger, cant remember now), and the SWG is a ASTRAL E25 (e35 available)...