# 4+ hours for an inch!



## Apj101 (Jun 19, 2020)

I have in ground sprinkler in a new construction here in NY
16,000st ft lot. 8 zone system, about 5 "spouts" per zone. 
Lawn has been looking a little stressed with all this heat so I decided to put a bunch of shallow square sided sandwich tubs out there to measure how much was falling. I left running for 1 hour and pretty much every tub had only 7/32 of an inch. That would suggest the system needs to run for 4+ hours to drop in inch. That feels crazy?! 
Could I have done something wrong?


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## Pete1313 (May 3, 2017)

I set my system up where it takes 5 hrs per zone to put an inch of water down. It is why doing an irrigation audit and checking how much water you actually put down is important. Every system is different. I set mine up with a low precip rate for two reasons. Less runoff on my sloped, slowly draining yard and so I can get more coverage with less zones on 38k sq ft with a 15-16 gpm maximum flow.


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## davegravy (Jul 25, 2019)

My system I'm designing is 7 hours per inch. I'll have to split watering up to 0.5" twice a week and water different zones on different days. Such is life with a tiny (low flow) supply pipe from the city.


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## Utk03analyst (Jun 8, 2019)

I'm pretty sure there's math that you can look at how many heads you have and the gpm of your nozzles and the sqft you are covering to figure out how many minutes it will take to get an inch, which would assume even coverage. I've tried it I think I have decent flow on city water roughly 12 gpm but it sill takes hours for me to get an inch down and with cycle and soak it seems like an awful long time. I currently run my system every other day really every day split into two schedules with rain and wind skip. I kept my TTTF green all June and the Rachio has been skipping as we've gotten more rain in middle TN in June. Just trying to keep it out of dormancy and unstressed to handle the heat and humidity in the coming months to try to prevent fungus. Had a few bouts last year before irrigation install that I won without losing any turf but it wasn't a fun endeavor.


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## Green (Dec 24, 2017)

4 hours is slow enough that it should all soak in. At higher precipitation rates, that can be a worry. When I use my oscillating sprinkler, I run it about 5 hours for a half inch with awesome results...nice and slow.

Most likely you won't want to water for the full 5 hours this time of year anyway...maybe 1/3 to half of that, at 3 times per week when it's sunny and hot with no rain. Depends on soil type, root depth, and evapotranspiration per day.


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## TSGarp007 (May 22, 2018)

Utk03analyst said:


> I'm pretty sure there's math that you can look at how many heads you have and the gpm of your nozzles and the sqft you are covering to figure out how many minutes it will take to get an inch, which would assume even coverage. I've tried it I think I have decent flow on city water roughly 12 gpm but it sill takes hours for me to get an inch down and with cycle and soak it seems like an awful long time. I currently run my system every other day really every day split into two schedules with rain and wind skip. I kept my TTTF green all June and the Rachio has been skipping as we've gotten more rain in middle TN in June. Just trying to keep it out of dormancy and unstressed to handle the heat and humidity in the coming months to try to prevent fungus. Had a few bouts last year before irrigation install that I won without losing any turf but it wasn't a fun endeavor.


96.25 * GPM / Area (square feet) = in./hour


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## Krs1 (Apr 2, 2020)

I'm on the entire end of the spectrum. I have 250sqft with 21 heads due to a very complex layout. Takes me 18 minutes To achieve 1" of water per zone.


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