Precipitation Rate/Catch Cup Test

Since you describe early on the post that there was lots of mist try to re-adjust the radius if you are having lots of mist I have My set to heavy droplets :droplet: no mist at all

@Anthony The radius is limited by the landscape. In some cases, you don’t want to be watering on fences, street, hardscape, shrubs, etc… Unfortunately some radius needs to be much less than what the Rainbird 5000 is designed for. And when the screw is adjusted to what the landscape requires, the rotor does not function well, and result in a lot of misting. Some rotors I have barely make it to the Rainbird 5000 minimum threshold, and they work very nice, and like you said large droplets, and you can see the water curtain… Those are few, and it is not possible to mix and match different types of sprinkler heads on the same zone, and it is a challenge to match precipitation rates even if it is all Rainbird 5000 but I can’t use a larger nozzle.

Our yard has the Rainbird 5000 heads installed in the back yard. I don’t remember what nozzle sizes were installed when we moved in but most of the heads were over-shooting and couldn’t be adjusted down far enough. I went through last year and replaced the nozzles with lower ones that were more appropriate for the distance required. This year I’m finding a few dry sections, one of which I determined was because the stream wasn’t misting at all (the adjustment screw was completely out). I went up one nozzle size and was able to adjust the range correctly, and the spot seems to be recovering. I did the same for a couple other dry spots but it hasn’t been long enough to see the results yet.

YMMV, but it seems you need some adjustment to create misting over the distance you’re spraying.

@moisture - that was one the reason why I changed all my old rotors and spray bodies because it was all mix in one zone I had hunters rotors and the toro spray bodies and hunters 360

The reason why I when with the rainbird 5000 + and the RD 1800 series and the R-VAN nozzle is because they match the precipitation on the 5000 +

@Anthony - so yes, I am going through the same exercise. I was debating between Rainbird and Hunter, and finally opted to go with Hunter. It is the same thing with Hunter, you can have the small yard rotors PGJ combined with the larger ones PGP with the proper nozzles. So this can be a good combination in case some radius is large and can work with the bigger rotors. When I had work done in the yard, the irrigation company installed Hunter PGP in some places, and they are mixed with rainbirds in the same zone! Anyway, I am planning to use these PGP in some places.

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This is a great conversation. Lot’s of helpful knowledge and input here. I only use Rain Bird 5000 PCSAMR+ rotors. My opinion of the radius adjust is to only use that screw to hold the nozzle in. Most cookie cutter builder installers use one nozzle in all rotors and use that screw to adjust there head spacing issues. (I’ve got a soap box for this, but I’m stepping back down.)

I believe the diffusion of the nozzle pattern with that screw ruins coverage and precipitation rate.

Nozzle correction and pressure regulation is the key to optimum precipitation rate. And of course the correct head and head to head spacing on the initial installation.

I’ve been correcting a lot of issues lately with zones that were over sized trying to stretch coverage. These installers seem to think everything is equal.

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Did you manually adjust your run time to 54 minutes? Or is that what Rachio came up with. I have Sandy Loam as as well and my run time is only 30 minutes. I’m curious what you have your crop coefficient and precipitation rates set at.

@haemorrhage - the run time was what Rachio gave me and I stick with it because the grass is greener than ever before for the crop coefficient I use this charts

Turfgrass Crop Coefficients (Kc)

Right now I have my crop coefficient set at 104% and it seems to be doing a great job as to my precipitation rates I have it set at 0.61 And the AWC at 0.15 in/ here is a pict of two of my zones


Thanks. Looks great. What is the water pressure in you house? I did a few catch cup tests, and I have a feeling my precipitation rate for my Rainbird 5000s is quite a bit lower than the default Rachio setting.

My house water pressure is at 60 psi what nozzle are you using ?? And did you have the precipitation rate as default ??

Ya, it was at default. My precipitation rate is around 1.8 cm/hr from the catch cup tests I did this week. My house psi is 75. I am not sure which nozzles the heads are.

You can use the rainbird nozzle charts to identify wich nozzle you are using with your system

https://www.rainbird.com/products/5000-series-mpr-nozzles

@Sprinklerman - good choice :+1:

I just checked a bunch of heads and the nozzles are all blue. Is that just a standard nozzle on the 5000? Blue isn’t in the chart.

Edit: found it. They are dark blue 2.0

https://www.rainbird.com/products/rotor-nozzle-tree-5000-series-rotors

Thanks for your help Anthony! I’ve learned more from you today than I have the past 2 years playing around with setting on my own.

My came with the red 2.0 nozzle install I’m glad you found it on the rainbird site

You’re very welcome @haemorrhage - good luck and happy watering happy Father’s Day :man: to everyone

I’m thinking the same thing about the radius adjustment screw. I’m going to back them out far enough to where they are just holding in the nozzle and run the catch cup test again. I’m also going to change out my 360° rotor nozzles from the 2gpm to at least a 4gpm, possibly 6gpm.

I think this would help balance the precip rate and it’s how it should be done. For example: A row of four rotors. Two 180s on the ends and two 360s in the middle. The 180s would get a 2gpm nozzle and the 360s would get 4gpm nozzles.

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2 of my zones only have 180°’s and 90°’s. 2 other zones have both of those and a 360°. What is the smallest nozzle you would go with on the 90’s and work up from there for the zones with a single 360? Would you go 2,4,8 or 1.5, 3, 6?. I’m thinking I couldn’t go up to an 8 because it would go over max gpm for that zone. For one particular zone I have a 360°, 3 x 180°, and 1 x 90°. That would put me at 22gpm!

Right. Don’t max your gpms. Best to be efficient and effect, then adjust your water times to give the grass what it needs. 1.5, 3, 6 look good, if this doesn’t max your flow and your getting head to head coverage.

If I did 1.5,3,6 for that particular zone I would be at ~17GPM which I think is still too high. The problem is I have no idea what my max GPM for the system is, and running a bucket/spigot test is going to be much lower than what’s going to the system. I have 5/8" copper supply pipe going into my 1" irrigation main line with a 25-75 psi pressure regulator. Would the bottleneck there be the copper or the PVC? It looks like 3/4" copper you can do around 11GPM, but with 1" PVC (or copper) you could do 18GPM. So based on the 1" PVC the 1.5,3,6 looks doable. I’m I way off here?