# New build questions



## Jr2169 (9 mo ago)

Just had a home built and decided to diy the irrigation. Especially with labor prices being so high here in west texas right now. Ive got roughly 20k sq ft of lawn to irrigate. The house is on 1 acre and a well. I wanted to make sure I measured correctly for the psi and gpm and maybe get some insight on my current plan. I used the wet method to figure psi and gpm via irrigiation tutorials.com. I cut in a T right after the well head for the irrigation supply and installed a brass cutoff valve. From there I cut a piece of pvc 8 inches long and attached to the T followed by the pressure gauge, 2nd 8 inch piece then cutoff valve. 2 L's after to get the water up and into a bucket. I ran the water until the pump kicked on and measured right at 40 psi to keep it running and accurately measured 5 gals at 17.6 psi. I attempted the dry method using the same tutorial and my numbers were off for sure. Is the wet method accurate enough to use? Do i need to figure the house main for loss considering the irrigation supply comes off before the house?

I want to use rainbird 5000 series sprinklers and planned to try to use 1.25inch sched 40 for main line. Ill end up with close to 400 ft of main and checked the chart for velocity and losses and with lose almost 7 psi at the end of the main and velocity will stay under 5fps. If you guys dont know already, wind always blows here in west texas. So im trying to decide on spacing as well. I originally planned for 20 - 23ft spacing. Most of my neighbors are at 20ft but it feels like thats overkill especially with the 5000 series heads. Thoughts on that in the wind? I ended up with a large amount of sprinklers on my plan and want to cut some out to save money but do not want to risk problems with the wind. Ive got a rough draft drawing on graph paper I could scan and upload at a later date but Im out of town currently.


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## Grizzly Adam (May 5, 2017)

I am in the finishing stages of my install (installing correct nozzles, aiming and adjusting pressure). My system was planned on 42 PSI and 10 gal/minute. Your 5g/min seems really low-- IIRC Rainbird refuses to design system for less that 8g/min. You would definitely have to install more zones to keep your pressure up. For the wind, up low profile nozzles to keep the spray low.


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## Jr2169 (9 mo ago)

Grizzly Adam said:


> I am in the finishing stages of my install (installing correct nozzles, aiming and adjusting pressure). My system was planned on 42 PSI and 10 gal/minute. Your 5g/min seems really low-- IIRC Rainbird refuses to design system for less that 8g/min. You would definitely have to install more zones to keep your pressure up. For the wind, up low profile nozzles to keep the spray low.


I think you misread that lol. I measured the flow into a 5 gal bucket. 17.6 gpm is what im getting. Good call on the low profile nozzles i hadnt considered that


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## Grizzly Adam (May 5, 2017)

Jr2169 said:


> Grizzly Adam said:
> 
> 
> > I am in the finishing stages of my install (installing correct nozzles, aiming and adjusting pressure). My system was planned on 42 PSI and 10 gal/minute. Your 5g/min seems really low-- IIRC Rainbird refuses to design system for less that 8g/min. You would definitely have to install more zones to keep your pressure up. For the wind, up low profile nozzles to keep the spray low.
> ...


Yeah, I must have! I highly recommend the Orbit manifold set up BTW. Very clean look and the ability to take it all back apart when you need to service.


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## Jr2169 (9 mo ago)

So quick question. The wet method is more accurate for well output measurement. Im sure I figured the dry method incorrectly because Im getting almost 18 gpm at 40 psi off the well. My poc is a T that comes off the well head and the house main. Im getting around 10 gpm figuring the dry method. Im misunderstanding something when it comes to figuring that via irrigation tutorials. Is it safe to assume i can design off the 18gpm? I followed the instructions accurately on the tutorial and closed and opened the line until the pressure remained the same and my well continued to run. I watched the meter on the well and also at the pressure tank. Both stayed right at 40 psi and the pump ran continuously. Ive already started designing based off that pressure and flow just dont want to have to start over. Any help is appreciated!


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