I'm going with home built this year. I have never had an accurate guess as to my gph, or how much sap I boil because as I boil, more sap is filling the tank constantly.
Right now what feeds my evaporator is a ss warming tank that holds about 6 or 7 gallons. I use a sump pump from my storage tank into the warming tank when that runs low.
What my plans are for this year is to add a clear plastic hose to the bottom of a 5 gallon pail, directly above my warming tank. The hose will go towards the warming tank with a valve on it. As I run low in the warming tank, I can fill the bucket to exactly 5 gallons, and then dump it into the warming tank.
Not sure if this will be ideal or be a pain in the rear, but I figure it might work.
95 taps on tubing, 15 gallon jugs
12 check valve taps on 1000 feet of 3/16 tubing currently getting better results per tap than the 95 taps I have on my 5/16 setup.
2x6 W.F. Mason Drop Tube Evaporator with a blower.
12"x24" W.F. Mason finisher.