Wow...I have to put that post in my notebook. Thank you. The nozzles I am using are TS Country wide ST 80-01 Orange. The capacity is .09 GPM at 30 PSI and at 5MPH 5.2 GP Acre. so multiplying times 7 heads =35.4 GP acre dispensed. Max shown is .14 GPM @75 PSI or 8.0 GP Acre @ 5MPH. with a 60 gal tank, I could cover 1.69 acres per tank at the 30 PSI setting. So with 24d applied at 32oz of 24D per acre recommended , I could expect to use 54 1/4 oz per tank as a ballpark mix or conversely 8 GPA * 7nozzles =56 GPA divided by water in tank (60) 56GAL /60*32 = 30.8 Oz of 24D at 75PSI pressure. I would like to figure the best setting so I don't have half a tank or spray left over and wasted. So somewhere I need to build a calculator (maybe using Excell?) to do a rapid conversion once I run the test at each PSI. Then regardless of what I am spraying all I would have to do is plug in the recommended dose and sq ft to be sprayed. So.....you are correct....the first item on the agenda is to accurately gage the liquid disbursement per 1000 sq ft , the MPH, and the recommended dose. The RPM has no bearing except to spin the pump and produce sufficient power.