I just replaced my old 1.5 HP Hayward Super pump with a Pentair VS 11018, with the old Hayward the DE filter would show a PSI of around 10 to 15 and now with the Pentair I need to run the pump at 2400 RPM to get that same 10 PSI, which does not save much money. I have read that these VS pumps should be able to run around 1300 RPM and when I set mine to that the filter reports 0 PSI.
I am not sure if this is normal, the plumbing is PVC 1.5” except for the return which is old copper pipe around 1” to 1.25”. The flow appears ok at 1300 RPM but I am not sure if it is filtering properly as I get Algae buildup during hot days. What is the best way to calibrate that I am getting the proper turn over. I have a fairly large very old pool – 15ft wide x 35 ft long and 10 ft deep in the deepest to around 4 ft in the shallow.
Any help would be greatly appreciated.