I replaced a Hayward 1/2 hp superpump on a 20000 IG pool with a 1 hp Hayward Tristar ee,my pump pressure on the old pump ran at 12psi but the new one runs 20 psi after a good backwash on sand filter, nothing else has been changed on the pool and I am considering changing the impeller to a 3/4 hp one, What do you think and how will this effect stress on the motor and energy efficiency. I would appreciate anyone's thoughts or ideas