Do you know your max gpm available? Sounds like you may need to add a sprinkler to better cover that spot. Your could also swap out all the VAN nozzles for the rainbird rotary nozzles. They give better (and larger radius if necessary) coverage, use less gpm (may have to water longer).

I did that to one of my zones recently. It was a zone installed prior to me buying my house. I knew I had too many sprinklers on one zone. Interestingly, despite using less water, the new rotary valves wouldn't pop up or spray far enough after I installed them. Luckily I had already planned on capping off several sprayers about to be replaced by a drip zone. So those rotary nozzles may be more sensitive to water pressure requirements than the VAN nozzles, that's my guess anyway...

 

Thank you for replying TSGarp007

I am unsure on the GPM, I bought the tool to test for it, however the connection is not easily accessible. I know it runs on it's own meter, but know that's not very useful.

I do not know who designed it, but they sure did not put much thought into it. Most areas are setup perfectly and do a great job, but then others are spaced out way to far. I find if I put a higher VAN head on it then creates a dry spot around the sprinkler itself.

Currently in the warmer months I run each zone 5-7 minutes...this cause some to dry and die off and others for the grass to become water-logged (turning yelllow/rust with any moisture). I aerate the park monthly/bi-monthly, but it only helps a little.

My thought was to replace 2 of the VAN's with Rotary 32SA's. Otherwise I am not sure there are any other work arounds?

What about closing most and putting in the Maxi PAW's in?

I installed my own system with little difficulty, but this park has me banging my head on a desk. Either I am giving it a fungal infection or I am slowly killing it by drought.

 

Where in that picture are the trouble spots?

You probably don't have head to head coverage, which is why the larger radius VAN nozzle leaves a dry spot close to it. I'm still wondering if switching to the rainbird rotary nozzles would help...

 

Can you try the Rainbird u-series nozzles? They have two orifices, one far one close.

Or try rvans, the rotator nozzles. Their precipitation rate is much lower so you'll have to increase the watering times. But they do seem to vary the spread better than old school van nozzles.

 

I was also going to suggest the rainbird U series dual spray nozzles. They are designed to help with dry spots next to the head.

 

Where in that picture are the trouble spots?

You probably don't have head to head coverage, which is why the larger radius VAN nozzle leaves a dry spot close to it. I'm still wondering if switching to the rainbird rotary nozzles would help...

The trouble spots are the brown spots I added on the photo (sorry they are hard to see). I am thinking that I may try switching to the rotary nozzles - at least on the zones that are way to spread out. I know the grass looks good in that photo, but I was over-watering it and caused the grass to start turning yellow anytime it was watered.

 

Can you try the Rainbird u-series nozzles? They have two orifices, one far one close.

Or try rvans, the rotator nozzles. Their precipitation rate is much lower so you'll have to increase the watering times. But they do seem to vary the spread better than old school van nozzles.

I will have to do some research on them, they sound like they would work well - so long as they can still throw far enough. It is funny that I can come here and get all these answers, but different irrigation companies have come and changed the VAN heads around and when that fails their only answer is "let's dig a new system".

 

Can you try the Rainbird u-series nozzles? They have two orifices, one far one close.

Or try rvans, the rotator nozzles. Their precipitation rate is much lower so you'll have to increase the watering times. But they do seem to vary the spread better than old school van nozzles.

I will have to do some research on them, they sound like they would work well - so long as they can still throw far enough. It is funny that I can come here and get all these answers, but different irrigation companies have come and changed the VAN heads around and when that fails their only answer is "let's dig a new system".

well i'm just a home owner who inherited what my current service company called "not an ideal" setup. they do claim to not have been the installer, and i'm not sure who was since i have no paperwork on it. i have been working to make it more ideal by raising, moving, and changing nozzles...including this seasons swap from VAN to R-VAN. about all the service company does is aim the existing heads, change leaking bodies, and winterize.

it is quite possible the companies don't carry U-series nozzles on the truck and just the VAN, etc.

 

Hopefully you are allowed to spray across the sidewalk? If so you can get some head to head coverage a little easier. I would plot it out and try and get head to head coverage the best you can from the R-VAN series nozzles (e.g., i'm guessing all the blue will be R-VAN24). There's a chance you'll have enough water left in the yellow, blue, or red zones to tap in and add a sprinkler somewhere if you have to. The purple zone has a lot of sprinklers on it. MIght be handy to have some of these: 1800XC. They can cap off some of the 1800 spray bodies so they don't spray water. When I converted my VAN zone to R-VAN, they weren't popping up all the way. The zone was way overloaded, I already knew. I switched to R-VAN to try and reduce gpm through the zone, but ironically it seems like they were more sensitive to low pressure available gpm and would not operate correctly. I capped off several of my other sprayers (replaced with drip irrigation zone separately) and the R-VAN started working normally. Without knowing your gpm available there's no way to tell in advance if you'll have that problem, and I don't know if that is a normal problem or for some strange reason only happened to me.

 

Those dry areas look like a design issue with inadequate coverage of the areas. They are probably only getting water from 1 or 2 heads. Ideally, you have 3+ heads covering every area. All of the brown areas are at the edges of zones, or in areas where spacing is much higher. I would bet that they are getting 1-2 heads watering those areas.

Your best solution woiuld be to add heads to improve coverage. If you have zones with too many heads and adding will cause problems with heads not popping up because you don't have enough flow volume, you need to move to heads/sprays that have lower flow and precipitation rates or decrease the number of heads on that zone. Switching from sprays to rotators may help in that case, but you will need to run the zone longer to get the same amount of water to the lawn.

This page: https://www.irrigationtutorials.com/sprinkler-coverage-nozzle-selection-sprinkler-spacings/ at Irrigation Tutorials should help, but it is fairly long.

 

Thank you all for the feedback. I feel a little silly, but I was completely unaware about the possibility of changing the heads to rotary heads, without changing the bodies. I am going to order some to have on hand.

If the new U-Series are inadequate, I will change them out for the rotary ones and set out my wife's snapware to measure how long I need to keep each zone on for.

Another, probably dumb, question is last year I noticed that anytime the grass would receive water (sprinkler or rain), it would look yellow and develop rust. I use milorganite and apply every 6 months during the warm months. Is it an issue of too much water or Fertilizer or even Thatch?