SPRINKLER TALK FORUM - You Got Questions, We've Got Answers

I have a well pump on my property and a pressure switch (on 40 PSI off 60 PSI).

I have tested my static pressure to be 48 PSI using my outyside spigot (on 1/2 copper pipe).

I do not know my current GPM , but based on 1" inlet pipe, am guessing about 15 GPM.

I am at the planning stage for my irrigation system (0.92 total acre).

I plan on having my plumber install my backflow preventer and then I will install the system myself.



Short of knowing my working pressure and my GPM, I want to make the following assumptions:

Design for 40 PSI pressure and 13 GPM using 1" PVC pipe

Change my pressure switch on from 40 to 50 and off from 60 to 65

Use the flow control on my valves to regulate the pressure to 40 PSI.

I have 4 areas and 10 zones in my design.

The average GPM is 9 in the other 8 zones (never exceeding 10).

I have 2 other zones where the GPM is over 16.5 and 16 - I need to combine these into 3 zones

Pass-1

Thanks for all of your advice.

I am working with a local specialist with lots of sprinkler installation experience in the area.

He has done a few plumbing upgrade for me already.

He did say the pumps used in the area are generally 1 HP and I should expect aboyt 13 GPM and be lucky to get 15 GPM.

My plan was to have the backflow installed and then test for the actual GPM.

He did tell me about raising the pressure settings on the pressure switch.



As far as the othe questions concerning the well, I moved in the house about 2 years ago and may be able to locate the company that set up the well and ask question. In the area, most of the homes (well over 90%) do have a sprinkler system install and are using well as well.



The only expense I did not anticipate is iron in the water that potentially will turn the sidewalk, white vinyl fence and the side of the house a "redish" color. My local expert is already looking for a system for me. He did mention a dual tank solution that switches off/on to backwash and keep up with demand etc. That sounds expensive. He will test the water today and let me know what the iron level is. Currently, I have a low PH issue that is beng managed by soda ash. We know that because the sink, tub and toilet turn a bluish color if not treated. But there's no visual evidence of any iron issue from the well.



So far, my irrigation plan call for 15 zones, with 7 zones on the iron treated backflow and the other 8 zones on the 2nd backflow (not being reated for iron). This will be used in the back of the house where there's no potential staining issues. Because I did not anticipate any iron issues, there's no monies allocated for that (yet). So the plan is to install the 2 backflows anyway and connect them to the main line. We will provide aifrastructure to split these in the spring (1 using the well water directly and the other being treate/filtered for iron when more monies become available.

Quoted from "Wet_Boots"

Make the tie-in first and then measure what is produced - that way you assume nothing. Then you can design your system.

Wet_Boots

Thanks for this suggestion.

My plan was to have the backflow installed and then test for GPM and pressure.
The design specification is all done.

All I need to do is to verify GPM and pressure.

I am meeting with the local expert today to go over details.