Sprinkler head recommendations

[Marinegrunt]

I've been studying up on the irrigation tutorial and plan on installing a system on my own. I also plan on pumping from our pond. It's located 50' lower than our yard. I have the calculations figured out and have been in contact with a pump manufacturer. The pump i plan on using cam supply 18 gpm and 44 psi at 160 feet of head. I can also have a different impeller installed and get 15 gpm at 55 psi or 12 gpm at 65 psi. Those numbers are calculated based on the 60' drop and for pipe friction loss. I realize i might have to decide after I design the rest of the system. Can anyone recommend which gpm and psi would be best to start designing with? I think 44 psi is the minimum for rotors so I'm thinking the 15 gpm at 55 psi would be best.

Can someone also recommend some sprinkler heads to use? We have about 8k to irrigate and is basically an "L" if you don't include the backyard. The backyard is small at around 800 sq/ft and is a perfect rectangle. The front yard is about 40 x 40 if you only measure to the edge of the house. The side yard, continuing to the front yard to the street, is about 60 x 100. I didn't know if measurement and yard shape would help with sprinkler head choices.

I can post a sketch of the yard when we get home from the in-laws in a few days if it'll help.

It seems the Hunter mp3000 may be a good choice for most of the areas. Thoughts?

I still have a lot of reading and figuring to do but I'm definitely learning. I was just going to use our town water supply but we only get like 7-8 gpm. I know it's workable but a pump makes more sense to me plus our water bill won't increase.

Thanks!

[andy10917]

I've done two different systems on my property (1 acre, 3 yrs apart) and just combined them a couple of months ago. My home water supply (valley floor in a low-mountains town) is 14 GPM at 63 PSI. I used all Hunter PGP heads - they're inexpensive and high-quality.

I can get 52' of throw from the head, and you don't need that, so I wouldn't trade in PSI for GPM.

I *love* Sprinkler Warehouse as a vendor - big selection, good prices and fast turnaround.

[Riverpilot]

I'm not sure which part of central IL you're in, but if you have a Site One (used to be John Deere landscape) near-by, they normally have most if not everything you would need to install an irrigation system. Pipe, heads, controllers, etc..
If you start up a relationship with them, tell them who you are, what you need, etc.. there's a good bet they'll give you the employee discount prices.
If you don't have a Site One, I've also used Sprinkler Warehouse.

I've been using my local one for a few years, and they bend over backwards to help me out anyway they can despite being only a "homeowner".

[PW405]

If you're going with rotors, I've really liked the Rainbird 42sa+ and 5000. From what I can tell, they are the same model. The newer ones have a "slip clutch" that allows you to aim their left/right stops without needing to rotate the entire body, or dig them up. Can be a big time saver if you ever need to re-calibrate for any reason.

[g-man]

I hope my post makes it thru. Some are going into the twilight zone.

When you say 44 psi @ 18gpm, is it the output from the pump based on the pump curve? Or is it what it will be based on the calculated value at the irrigation valve?

Consider a filtration system and the effects it has on flow and pressure. If possible, do the pump and pipe install first, and get an as built pressure and flow before installing the irrigation system in case you get less flow.

If I had to pick right now, I would go with the higher pressure, lower flow. I could always add a zone in design but adding pressure later is harder/expensive.

[Marinegrunt]

Thanks for all of the help. I wondered about the psi vs gpm because the irrigation tutorial says rotors need a minimum of 44 psi. That 18 gpm is at 44 psi so I'm right there. The gpm and psi I listed are at the sprinkler heads. Well, that's what the pump manufacturer told me.

I was thinking that it might be a good idea going with the 12 gpm at 65 psi anyways because if for some reason I ever decided to switch from the pump to my water supply I could probably pull it off without changing too much with the system.

I need to check out the heads you guys mentioned and run the numbers. I also like the idea of running the pump to see its exact output and with a filter. Real world is always much different than on paper. I better get it ordered with the right impeller and soon.

Thanks

[ken-n-nancy]

I've been studying up on the irrigation tutorial and plan on installing a system on my own. I also plan on pumping from our pond. ...

Can someone also recommend some sprinkler heads to use? ...

I still have a lot of reading and figuring to do but I'm definitely learning. I was just going to use our town water supply but we only get like 7-8 gpm. I know it's workable but a pump makes more sense to me plus our water bill won't increase.

Sounds like you're considering all the options and thinking this through before you do it -- that's excellent!

Just a few thoughts that came to mind for me after reading your posting. Just FYI, we have irrigation for 12500 square feet from our residential domestic well. Our system is set up to run on 5gpm at 45psi.

1a - Irrigation can take a lot of water. Depending on how big that pond is, and whether or not it has inflow and outflow, it may not be able to support your irrigation needs, particularly in drought conditions, which is when you most need irrigation. Accordingly, I'd suggest designing the system to be able to work on *either* the town water supply or the pumpwork on the town water supply. I'd also suggest actually plumbing the system up to both, with backflow preventers where needed to allow that to be done according to code. In that way, when the pond has water, you can use that to irrigate and save $$$ vs. the town water. When the pond doesn't have enough water for you to use to irrigate, you can flip some valves and instead use the town water to irrigate.

1b - In order to set up the system to work sourcing water either from the pond or the town, you'll need to design for the lower gpm and the lower pressure. I'd suggest choosing a pump which matches the town pressure, and then using the lower gpm as the design point. The low gpm will limit the number of heads you can put on each zone, and limit you to using small nozzles. Personally, I like the small nozzles, as even though it takes a long time to get 1" of water down, it is delivered very gradually, so there is ample time for the water to soak in rather than run off.

2 - When our irrigation system was installed, there was a mix of Hunter PGP and Rainbird 3000 heads. I prefer the Hunter heads and have since converted most of our heads over to Hunter PGP or I-20. I ended up upgrading many of our heads to stainless Hunter I-20 heads for the "head shutoff" feature at the head. That feature is nice if one is doing a renovation where one wants to irrigate just part of a zone. The "germination watering" that one does for three weeks while waiting for KBG to germinate does a real number on existing turf that is covered by part of the same zone that is being used for germination watering.

3 - When deciding your zone layout, consider which sections of the lawn make sense to water together. Each zone should be a section of lawn that it will make sense to water all together -- you don't want a zone to have half of the zone in full sun and half in deep shade if you can help it. Also, if using rotors it is best to have quarter-turn and half-turn heads on a zone with only quarter-turn and half-turn heads; keep the full-turn heads (if any) on a zone with only full-turn heads. Full-turn and half-turn heads can be put on the same zone if needed, but you don't want a quarter-turn head and full-turn head on the same zone if you can at all avoid it, as it will be difficult to match up the nozzles on those, particularly if dealing with a low overall gpm from your supply.

4 - I'm sure you'll see this everywhere in the irrigation tutorials, but you really do want to design for head-to-head coverage. Not doing so is a common newbie mistake.

Just my two cents...

[ken-n-nancy]

Accordingly, I'd suggest designing the system to be able to work on *either* the town water supply or the pumpwork on the town water supply.

Above should have said,

"Accordingly, I'd suggest designing the system to be able to work on *either* the town water supply or the pump from the pond."

Another thing I should have mentioned, though, and is a complicating factor, is that the system should also be designed so that the pump runs continuously. If you choose to have the system be swappable between pond-sourced water and town-sourced water, the pump will need to be chosen such that it runs continuously when delivering water at the gpm and psi of your town water.

[andy10917]

K&N - is that in sq ft?

[ken-n-nancy]

K&N - is that in sq ft?

Seriously, though, this inability to edit posts for more than 5 minutes after posting is really a frustrating factor for me. I keep telling myself to do all my proofreading before posting, but old habits die hard.

[Marinegrunt]

Sorry for just now posting. We were out of town and busy with other things when we got home.

Thanks for such a detailed reply Ken-n-Nancy! You covered a lot of great points. Thanks for all of the great tips and replies.

I took a look at the Hunter pgp heads and they seem to have a larger range of adjustment or have a broader range depending on applications. It seems like they would work in almost any situation. I think they seem like the way to go.

It's actually a lake rather than a pond but we can use it for irrigation or whatever we need. It's spring fed so water level doesn't fluctuate much. I think it's still a good idea to tie into our water main just in case but it might be a pain if I decide to do so. The easiest option would be to tie into the line in our meter pit unless I feel like ripping out drywall in the basement. I might install the pump main line near the house in a flower bed and worry about it down the road if I decide to tie them together. I'll have to think on that one some more.

Ken-n-Nancy....On 5 gpm and 45 psi, how long does it take to get your 1" of water a week? How many zones do you have and how many sprinklers per zone? We have a good sloped side yard so slow watering would be good. We also have 2 kids and a dog so I don't know if I want the lawn wet for half the week. I'm not too worried about that tho.

Can someone recommend some valves to go with my Hunter pgp heads I plan on getting? I don't need anything special or fancy unless it's something that might be worth considering.

Sorry if my reply is all over the place. I've been typing it off and on for 2 days whenever I had a minute.

Thanks!

[ken-n-nancy]

It's actually a lake rather than a pond but we can use it for irrigation or whatever we need.

That's reassuring. When you said "... our pond" I had the vision of a little decorative pond about 20 to 30 feet across and a few feet deep - I didn't think that would provide much for irrigation!

Ken-n-Nancy....On 5 gpm and 45 psi, how long does it take to get your 1" of water a week? How many zones do you have and how many sprinklers per zone?

Good questions. From the "sprinkler audit" we did a few years ago, I had determined that it took 5.5 hours to put down 1/2" of water across our entire 12,500 square feet. Accordingly, I water every 3 days (sandy soil) for 5.5 hours, which I thought provided 1/2" of water to our lawn.

However, a quick double-check of that from gpm and square foot calculations doesn't match, so something must be wrong somewhere. Showing my work so that you can make this kind of gross calculation, too: 12500 sq feet * (1/24) [for 0.5" of water] = 520 cubic feet of water. 520 cubic feet * 7.48 [gallons per cubic foot] = 3889 gallons. Laying down that much water at 5gpm would take 3889/5 =~ 778 minutes, which is ~13 hours.

So, something is wrong somewhere, probably with my "sprinkler audit" calculations. Either my pump is delivering more than 5gpm (which is possible, but not what we measured before putting in the irrigation system) or my sprinkler audit calculations aren't correct and I'm not really putting down as much water as I think - watering only about half of what I thought.

Watering for 5.5 hours works out pretty well -- watering starts in the wee hours of the morning (2 am) and is done not too long after day break (around 7:30am).

[rydaddy]

Late to the party, as I was on vacation and 'unplugged' myself from tech. I would use hunter I-20 6". my 2 cents.