Ok, I was told to check the gpm by cutting into my main line (1 inch) just ahead of the water meter and filling a 5 gallon bucket out of the 1 inch pipe. I put a "T" in the line and ran a piece of 1 inch pipe down off that with a 1 inch stop valve to check the flow. I filled up a five gallon bucket in 8 seconds. By the math 5 gal/60 x 8= 37.5 gpm. This seems like alot. I was told that the max safe flow is around 18 gpm. What does this mean? Do I need to get my gpm down to 18gpm, and if so, how? I was going to run the system with 1 inch poly and 3/4 inch laterals. Any help would be appreciated. Also, my pressure is 58 psi.