My apologies if this has been answered already but I searched everywhere and couldn't find it. I currently have a pentair clean and clear 75 filter with an Optiflo 1hp pump. The filter is fine but I'm looking to upgrade the pump to something better than a single speed. Everything I'm reading leads me to believe that I can get a dual speed but variable speed is for inground pools. I have an above ground 12x18 oval 52" deep. Any suggestions on what I can get that would be a simple swap out with the existing Optiflo?