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

Just to follow up on my issues. Been using the irrigation all summer, near as I can tell by the pressure at the sprinklers/rotors, I'm pumping out about 800 G/night for the irritation. Haven't had any issues with running out of water at the well. Finally installed a hydrant off the 1" line right after the irrigation filter and I fill up a 5 G bucket in about 20 seconds or less from that hydrant. So it appears the pump in the well is certainly putting out at least 15gpm, but only at around 40psi. Haven't noticed that the booster is lacking water at any time. So it appears to be working fine, but if I ever end up having to replace the well pump, I'll put in one that will put out the pressure without the booster. I'm still thinking about what to do in the house for the pressure, it's still only 40psi or less, but that's not what this forum is about.

I've installed a psi meter at the input and the output of the booster pump and also added a 1" valve for a separate supply to a hydrant I want to put in the garden the well is in. Anyhow running the system in the night at 1am, it runs for something less than 2 hours and according to my calculation it's pumping out about 1000 G of water each night. Now I may be a bit optimistic on that figure, but it's my best estimate with the output of the rotors/sprinklers at the 48-62 psi output of the booster pump. It couldn't be half that figure. Input psi runs about 36-42 psi and the booster adds about 20 psi or a bit more. I still haven't run the irrigation for an hour or more while I can watch it, but I did run it for 20 minutes once and the sub pump is keeping up and going on and off about every 4-5 minutes and the output of the booster is maintaining 45 psi or better. 20 minutes on a zone I figure it putting out about 15 gpm is 300 G. 300 G in a 6" well is about 200' of water and it's not showing any sign of drawing down the head. Since the well is 250' and the pump is at 200', it's certainly not drawing the head down to the pump. I know I need to measure the flow beginning and end to see whats going on, but at this point it looks like the well is certainly keeping up with the 15gpm. As soon as I can get a way to measure the flow and the wife stops doing laundry, I'll do a timed flow test while running the largest zone.

I found what looks like the specs on my sub pump and with 200' of head it should be putting out about 15 gpm. So things are adding up so far.

This is why I wanted more than just a word description. I've seen home construction that made conventional supply connections difficult or impossible. I've also seen supply connections that ignored the rules of common sense. Good luck with the system.

I suppose it could have been done that way, but it would require a lot of trenching under sidewalks and very deep too, messing up the existing gardens even more than they did. Maybe it will back flow the pressure tank mitigating some of the sediment? I wouldn't have let them do it that way, it would have been too much of a problem, maybe if we did it when the house was built, but that was long ago. It is what it is.

The point of the questions is to determine why it was not possible to make a connection point inside the house. Most houses have a utility room that people can walk into, where you would have the pressure tank and pressure switch. The point of connection would be just past the pressure tank, on the downstream side. The system point of connection would be at the pressure tank, and the supply line would run to an exterior wall, then outside to the backflow preventer.

Why prefer this? Easy access, for one. Also, when you tap a sprinkler system on the upstream side of the pressure tank, the water is flowing in a reverse direction from the pressure tank, every time the system turns on, and that is never optimal.

Yes, that's exactly how it is. The 1 1/4" plastic pipe comes in from the well to the utility space below the front door with the pressure tank there, no control box (2 wire), just the pressure switch on the tank, but it's about 7' deep there. Why would they want to tap in there and then have to ditch 7' deep and run everything back outside to the other side of the driveway again. Plus dig up a large concrete walkway to get to it. I don't think so. No way would I have let them put all that paraphernalia next to the sidewalk by the front door.

What's this got to do with gpm anyhow?

So, your house has no basement utility room with an exterior wall? Where you would have located the pressure tank and pump controls when the place was built?

The pipe at the well is only 3' deep and at the house about 7'. Plus the well is in a garden where there's plenty of room for all the auxiliary equipment. At the house, it's near the front door. Better away from the house than next to the front door with all that equipment. I'm not complaining about where they tapped into the line, it's only about 60' from the house to the well anyhow.

Still recovering from surgery, but plan is to install pressure gauges at input and output of booster, plus a 1" outlet at the input to the booster. Had a well guy tell me to turn on the water at the input to the booster and let it run until the pressure tank turns on. At this point, the sub pump will probably not keep up and pressurize the tank to 60# again and I should get a good reading of how many gpm right at the output of the well head the sub pump is putting out, at least for the 1" line. If I'm motivated, I'll measure the water height in the well, and let it run for half hour or more and see how much it draws down the head. If the sub pump is only putting out say 10 gpm and the well is supplying 40gpm, there should be minimum draw down I would think.

I'm pretty sure I'm going to get something like a 1 1/2 HP variable speed/constant pressure sub pump. That should put out about 15gpm or so and should solve all my dreamt up issues. At least I should have good pressure in the house which I've never had and it should be able to keep up with any of the zones I have.

One guy quoted me about $3K for the pump and installation.

What I don't see, is why a tee was cut into the outside well line, as opposed to drawing from the house, at a point just downstream of the pressure tank.

I'm sure the pump/well guys will have a field day with the system. Actually it's not terribly out of order, the house is mostly higher than the well head, but downstairs is below it. Some of the irrigation is slightly above the tap into the well pipe, but most of it is well below the well tap point. Most of the irrigation system is below the house including downstairs, but some of it is above the downstairs. I'll report on what I end up with.

I've got 2 guys so far to take a look at the system.

I plan on making a rather detailed story for Angie's List out of this "Irrigation Specialist" which I will also post here.