Oscillating moisture chart

The moisture chart for one of my zones looks really strange. Normally, I expect to see a gradual sloping down in moisture %, then when the moisture level is about to hit the AD level, the graph jumps back up to 100% (or so) and starts the gradual decline again. But in this case the graph is zig-zagging with watering events scheduled every other day:

Tried talking to Rachio’s tech support earlier, but the rep was giving me a lot of strange and seemingly unrelated advice, leading me to believe that she didn’t know what to make of it either. One recommendation, for example, was that the problem is that I have all of my 10 zones on the same daily flex schedule and that I need to move this zone into its own. ::man_shrugging:

I suspect that the reason for this zig-zagging is that the depletion (downward) slope is too steep and there is not enough “room” to let the depletion happen for more than 1 day. Which means if I change AD to, say, 60% the schedule should stabilize some. But I wanted to hear what others may think of this.

Thanks

The zig-zagging and sharp movements are due to the fact that the graph is based on calculations at the end of the day, the total of water removed from ET and added from irrigation and rain. Depending on the zone’s conditions, you can see a fairly constant slope (in fairly constant weather), then you’ll see an upward spike when rain or irrigation water is added.

Sounds like bad advice. Just because a zone is different doesn’t mean it needs its own schedule. The zone properties accomodate that.

That’s kind of it. The second chart shows a stabilized system where it irrigates one day, then 2 days later, the soil is dry enough that it needs irrigated again. You’re irrigating 0.24" per day, and your Crop Evapotranspiration (ET - the mount of water used per day by your zone) is averaging around 0.11" per day (5/17 to 5/21(, so with that weather, your system will water every 0.24/0.11 or 2.18 days.

As the weather gets hotter, you can expect it to water even more often, sometimes 2 days in a row.

There’s not necessarily anything wrong with your set or this graph. Increasing the AD to 60% or more will tend to water a bit less often, but you don’t want your grass too dry before watering. Ideally, a lawn should be watered 2-3 times per week, the preference being 2. But I suspect you have a lawn (a sandy lawn) that doesn’t hold as much water as a clay lawn like mine. My clay lawn’s available water is 0.17"/", while sand can be as low as 0.05"/". That means Sandy soil must be watered less deeply (as it doesn’t hold as much) and more often than clay. If you want to confirm any of this, please post a typical zone’s setting, and Advanced setting.

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