determine GPH???

Hi,
Can anyone help determine the GPM rating for my pump, it is a Hayward/AO Smith Power Flo LX 2HP motor, model SW1585x20.

I've checked every page of the manual and the Hayward website. How do I determine the GPM?

My ultimate need is to determine sufficient run time. All water parameters are fine, except skyhigh clorine. Water looks nice and clear.

TIA for any help.

You can call Hayward and ask for a copy of the pump curve (or look on the net)....you'll need that as well as the Total Head on your pool.