I went to a house today to take in all info. Pressure is 54. Gpm is 4.28. Am I doing something wrong? Surely it has more than 4 gpm. Method to determine gpm was a 5 gallon bucket. It took 70 seconds to fill up from the outside spicket. 300/70 = 4.28. Any help would be appreciated. Thanks in advance. By the way, if this is correct how do I go about designing a system that is on over 1.5 acres?