We have Pentair Tagelus high rate sand filter TA60d and variable speed pump. I was wondering what is best way to set up my two or 3 speeds that filter will still do its work. I know there are minimum and maximum pressures filter can operate at. Currently its set up to run 24 hours. it runs through the night at 1500 RPM then ramps up to 2000RPM for few hours and 3000RPM for the time pool is in use. I have been watching pressure gage on the filter and at 1500RPM pressure drops to almost nothing. Do I have to keep the pressure in certain range for the filter to actually do the work ? We are near Chicago so our equipment only runs for 4 month and then gets winterized. Any advise woul be great. I do not have flow indicator on my plumbing that is why I'm trying to figure that out with pressures.