Richard you were right, and yes it did make a difference. I measured one gallon in ten seconds (exactly), out of one of four outputs, then I multiplied that times four for a total of 24 gallons in a minute, and 1,440 gph. I am glad I recalibrated. Now I need to adjust my expensive gate valve to lower my flow. I owe that little pan world pump an apology I guess. I am figuring it out as we speak to get the correct flow.