I would like to upgrade to a variable speed pump. My current single speed pump has 1.5 inch inlet but the pool return has two 1.5 inch lines (one from skimmer boxes and one from drain). Those two 1.5" return lines are tee’d into a single 1.5" right before the pump. Should I get a 1.5" inlet pump or 2"?
You can get a pump with 1.5" or 2" ports. You’d have to use a reducer if you go with a pump with 2" ports.