So, my customer has about a 35000 gallon 20x40 inground with 10-12 total returns. Last year she replaced her liner and they also replaced the pump motor. The filter is a Hayward s244t sand filter, the pump is a Hayward Super Pump, and the replacement motor is 1hp. The pool has 2 skimmers and no main drain. The pool has a set of stairs with 2 returns, a swimout with about 6 returns, and 3 pool returns. Recently I fixed an air leak at her pump union. I thought it might help her circulation and it did, but it didn't cure her problem. I had to shut the valves for the swimout just to get a decent flow from the stairs and pool returns. IMO, even with the swimout returns closed, the flow is too low. 1hp just seems grossly undersized to me. Am I wrong? If I'm right, what size motor does she need? I thought a minimum of 2hp would be what she needs.