I'm still learning about wells, drilling, irrigation, pressure etc. so I apologize for my ignorance but I'm having trouble visualizing the 4' long skirt idea. Any pics?
We figured the 5hp would provide adequate volume gpm for the orchard setup. Approx 6500' of 1" poly and close to 2000' of 2" pvc.
Mark - I really like they idea of the digital pressure control and capabilities you have.
Sorry, it's 120' in the well now.
My Grundfos pump is 3" in diameter. I think me and my well guy clamped a 4" diameter by about 4' long piece of PVC pipe about 6" above the pump's intake. Believe we cut 6" long or so slits in one end so it would bend down and seal around the pump housing. (Was 12 years ago, brain farts ya know) The idea is that when the pump starts up it will torque and hit the side of the well sloughing off crap so by extending the intake 4' down with the extension you reduce the sand, limestone bits, whatever..... from being sucked up into the pump.
One of the benefits of the Grundfos is a 2 second slow start so you don't have the vicious startup hammer like you do with other brands. Best thing since ice cream.http://us.grundfos.com/products/find-product/sqe.html
Here's how to save a bunch of money. Call Grundfos up to size the pump. Buy your 301 system from ebay! Have a well man with a truck mounted derrick change out and drop the pump in. Cost me about $120 to pull the old pump, unscrew the old pipe casing, screw new to the new pump as he dropped it into the well and then set the well head cap. I used 20' PVC "sticks", 1 1/2" diameter, threads on both ends for couplers.
12 years ago I went with a regular Grundfos pump without the Constant Water 301 console for the irrigation system, used only a relay start up switch and Hunter controller and really did an "AW SHIT" afterwards. Tried to save money. The ability to be able to change PSI from 40 - 100 with the touch of a finger is sweet with the Constant Water system, plus once you set it you get the same pressure no matter if you're running a mile of line or 30'. Note - you won't need to T off with a 2.5 gal. hot water pressure tank since your irrigation system can be considered "not closed" unlike your house which is and needs the T tank pressure relief as PSI changes.