I also have a Northstar 2hp 2spd pump. Very happy with it. Sand filter 500lb and 2 1/2 piping. 4 returns, 2 step jets, 2 swim out jets, spill over spa. High speed 20psi and low is 8. Run it on high 1hr to start then low for 8hrs an high again for 1 hr. This gets the spill over going and moves everything to the skimmers. The low speed works well for the SWG and filtering.
Was a bit scary to see the Sand filter and pump lid flex when you change speeds thou. Moves an amazing amount of water.