I’m seriously considering replacing my one year old 1.5 hp Hayward Super Pump with a Pentair Whisperflo 1 hp uprated, two speed pump (WFDS-24). The thought of a lower electric bill appeals to me, but I really like the idea of a quieter, more efficient pump.
I've read the excellent "Hydraulics 101" thread several times, but still haven't figured out how to estimate the operating filter pressures with the new pump. My current filter is a Hayward S244T sand filter and it runs at 13.5 to 14 psi when clean. Any idea on how I would I go about estimating them for both low and high speed?