Here's a starting point on gallons per minute on different sizes of PVC
pipe. It won't take long for you to pump 380 gallons at much pressure at
all. A small pump will cost less than a big one. Shop for used, and you
can get a lot of value for your dollar.
The PVC people make pressure reducers to go into drip lines. They drop it
to the 20 psi range. If you use drip system, you can get by with a smaller
pump than if you want to spray over a lawn.
I did not read your recovery rate. That is, how long does it take to
recharge the barrels. If it is from rain, you might not have enough to
water regularly if you have much to water. If it is creek or spring fed,
you will have more.
Basically, if you are going to water plants, the gpm and psi don't matter a
lot, as they will be delivering water slowly. You can use different sized
emitters to get the right amount for each plant, and it won't make much
difference if it takes ten minutes or thirty minutes to pump out the
available water. If you have lawn to water or big sprinklers, you can go
through 380 gallons of water in thirty minutes on a 1" line.
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