Flex Daily set to run for 30 hours

Hi everyone,

I am using a Flex Daily schedule for the first time this season and some peculiar (to me) things seem to be going on with the scheduling. Couple of things to consider:

  1. I have 10 zones (including 1 zone of spray heads and 1 drip line)
  2. Rotor zones have an approximate precipitation rate of .25" per hour and the spray heads 1.3" per hour after conducting a catch can test. The uniformity was quite low.

As a result, I understand I can expect the system to run for quite a bit of time to hit an inch or more of watering.

The first time the schedule will run is on 4/21 where it will go through the 8 rotor zones for about 3 hours each with a run time just under 23 hours. The following week it will break the zones up over 3 days (makes sense given different zone parameters).

On 5/2, the schedule shows it again cycling through all the rotor zones (3 hours each over 23 hours) but then going through the spray zone and drip line over the next 7 hours with soak time breaking up the spray zone run. In total this will run for 30 hours straight.

My 2 questions:

  1. Will the rotor zones run continuous for 3 hours each without any soak time? I could see my yard easily flooding doing that.
  2. Is there a way to force the system to break up the zones over different days so as not to run for 30 hours straight? I suppose it does not matter as the cumulative watering would be the same but practically would not be able to be in the yard during those times.

3 hours at .25" per hour is of course 0.75" of water. That’s a LOT of water at one time. Can I ask what your Advanced settings are, and where you’re located?

Do you have any restrictions on what days Flex Daily can water? Any that are not allowed?

The soak zone can run for a very long time to get enough water out, but how much of the 7 hours is the spray zone? As it puts down 1.3" per hour I would think less than half an hour. Again, Advanced settings would help us understand your setup.

1 Like

I am located in northern New Jersey. My town has no water restrictions and have no constraints on my Flex Daily schedule.

The advanced settings for rotor zones are:

Available water: .17 in/in
Root depth: 5.9 in (3-way KBG)
Allowed Depletion: 50%
Efficiency: 16% - 35%
Crop coefficient: 78%
Nozzle inches per hour: .22 - .35 in/hour

The slope setting is either flat to slight for each. Exposure is lots of sun to some shade. Soil type is loam.

The spray zone:

Available water: .17 in/in
Root depth: 15.8 in
Allowed Depletion: 50%
Efficiency: 31%
Crop coefficient: 50%
Nozzle inches per hour: 1.3 in/hour

On the day the spray heads run, they are on for 17–18 minutes and soak for 30 minutes (5 times for a total of 88 minutes).

Thanks for that.

Okay, 0.17" of water times 5.9" root depth times 50% Allowed Depletion gives .5" of water per time. With .22"/hr that gives 2.28 hours, with .35"/hr that gives 1.43 hours. Times will be somewhat longer due to Efficiency and Sunlight.

I notice your efficiencies are really low. You used catch cups, and I’m sure your readings are right, but I’ve found that catch cup placement is EXTREMELY critical. You can have large swings in efficiency based on where you put your catch cups. Have you noticed some areas of each zone that absolutely don’t get enough water? If so, can they be corrected by adjusting the sprinkler heads?

My efficiencies are quite low on some zones too. But I’ve used efficiencies of 70-80% in the program because I’ve not noticed any areas that stay too wet or too dry, despite my catch cup measurements. Doing this will reduce your total watering time, reducing water usage. You can always compensate if you need to elsewhere.

Are your 8 similar zones on the same schedule? If so, the soak phase can be accomplished while other zones are being watered. If not, and if 2 or more schedules occur on the same day, one schedule must complete, including soaking time, before the next can start and it can take longer. That doesn’t mean that watering will always take place on the same day for all 8 zones; it just means they’ll be all considered when watering.

While variations in each zone can end up changing what zones water together, you can force them to be different by manually watering some zones, adding extra water to the zone and postponing watering of that zone. I do that once in a while, so all my zones don’t water the same day, taking longer than I’d like.

For the Spray zone, 0.17 x 15.8 x .5 = 1.34" of water at once, needing 1.34 / 1.3 x 60 = 62 minutes. Again, efficiency and sunlight will extend that. Application factor based on efficiency of 31% is 1.7, but 1.7 x 62 = 105 minutes, not 88 minutes. Perhaps it’s applying somewhat less than the 1.34". That’s a LOT of water to apply at once, so I’m guessing it is. That zone is apparently shrubs, which can be watered deeply, but that still seems like a lot of water to me, unless it’s a drip zone. I’m not as sure about it.

Right now, the National Weather Service for the northern New Jersey area, the FRET value is about 0.95" per week (go to link, in second dropdown, go to the bottom to Weekly FRET). For your Crop Coefficient of 78%, that means your 8 zones should get about 0.95 x 0.78 = 0.74" of water a week. With those zones getting about 0.5" per time, Flex Daily should be watering about every 0.5 / .74 x 7 = 4.7 or 5 days. It will get shorter as weather warms up.

For the Spray zone, you only need 0.95 x 50% = 0,48" of water per week. Applying over 1.3" of water at a time, again, seems way too high, resulting in watering only every 2-3 weeks, which doesn’t sound healthy for shrubs to me. If you’re sure of the 1.3" per hour, I’d reduce the root depth to maybe half of what is is, so as to water more often with less water. Just guessing here.

Hope this helps. Continue with the questions; I’m sure you’ll have them. :wink:

Thank you for your thorough response. I really appreciate the thought that has gone into your explanation.

I have pasted the water cup results to the bottom of this reply. I haven’t visually noticed any zone not getting enough water. There is head to head coverage for the most part but there are some areas where the outer edge of the zone is only hit by a single head (my property has an odd layout). My catch cup placement was fairly even (close too heads, at the extreme end of range and in between). The outer edge definitely gets more water than close in.

Zone 5 does have one area which I am having the irrigation contractor come and fix because they used 2 rotors in a 20 foot wide by 8 foot area of lawn and consequently they screwed the diffuser all the way down and that area gets drenched very quickly. They should have used MP Rotators.

In looking at the readings, should I delete the outliers? I realize the data is the data but that will improve the efficiency.

All readings in milliliters

Well, whether you delete the outliers, or as I suggested, just change the efficiency by increasing it, it’s fudging the data, isn’t it? I just think the efficiency may not be as important as the formulas make out, because if it’s that bad, yet you don’t notice an area over- or under-watering, then how can it? And I’ve seen huge differences by relocating the catch cups by just a foot or so.

All Efficiency does it /partly/ increase the watering time to provide more water, helping out the drier areas, but adding even more water to the wetter areas. I just use 70-80% and be done with it.

1 Like