That's how I see it Brian. You would have to know if the original poster was boiling raw sap, or concentrated sap, in order to come up with a GPH rate. Also, all the considerations berkshires brought up. I have a flat pan and baby sit it, running 1" depth. I also added a blower 2 years ago. That blower made a huge difference in GPH. I also preheat the sap, so the actual boil never stops. I'm never introducing cold sap to the pan. 2 years ago I was running a 3" depth in the pan, until a friend stopped by and told me to try less sap, but keep on top of it. So many variables, going from 3" of sap with no blower, to adding a blower, to going to a 1" depth, changed my GPH for the better at each change in methods.