Calculating flow rate?

[Jerry]

My pump's flow rate is not marked...How can I calculate the rate to figure hours of operation per day?

I't a Hayward MaxFlow 1 hp....3450 RPM.
It runs about 20-22 psi.

 

[spishex]

To know for sure you'd need a vacuum gauge to test your suction side pressure, but if your pressure side reading is accurate you're at about 46' + suction head. That would put you somewhere between 50 and 60', which for your pump is anywhere in the 27-50 GPM range.

This is assuming a max-rated pump (SF 1.0) and that your pressure gauge is accurate.