836 litres = 836,000 cm3 in 5 minutes or 12 times that in an hour or 10,032,000 cm3 per hour.
To calculate nozzle flow rate in cm/hr = flow in cm3 / area in cm2 = 10,032,000 / 3,465,000 = 2.895 cm/hr = 28.95 mm/hr = 1.14" per hour. Yes that sounds about right.
So the formula for mm/hr flow rate will be Total Litres Flow / Minutes run / Area in m2 x 60:
836 litres / 5 min / 346.5 m2 x 60 = 28,95, so that checks out.
(Apologies to everyone familiar with using the metric system, as this is no doubt obvious.)
For Zone 8, that gives 505 / 5 / 145 x 60 = 41.8 mm. While you mention this may not be completely accurate, it shows what I’ve known: similar systems with similar spray heads can have VASTLY different flow rates in mm/h.
Yes, along with calculating the area. That’s the easiest way to determine each zone’s Nozzle Flow per Hour to enter in each zone’s Advanced properties.
Just a quick update - our Mid Jan to Mid March bill has arrived. We consumed 134m3 which was half of last years amount for the same period, so we’re well on the way to payback already. I think we’ve covered the cost of the Rachio and the Weather Station already. We had the additional cost of wiring the secondary location with 8 cables about 140m to the main location to be able to run the whole site with the one single 16 zone unit. This was far simpler than installing two separate controllers.
I finally got all zones detailed and added to the yard map. Unfortunately, I still haven’t managed to get 3 or 5 min tests done for anything other than the initial 2 zones. If you want something done right, do it yourself !!!
True. But you’ve had several offers to go over and help measure the flows and zones, including from me. For the mere price of a few first-class air tickets, you could have all the help you want. Just don’t try to get rid of us when the job is done! lol!
Latest update - it’s been a fairly wet month and was pouring rain up until about 5 days ago. So correctly, all zones went up to 110%. By last night, the zones were all down to 0% and were due to water last night - but I hit Skip on the basis that there is more rain due in the next day or so, and I felt that, with the amount of rain that fell, it seemed odd that the evapotranspiration had already brought the zones down to 0% moisture.
I got someone to check the gardens with the handle of a wooden spoon this morning. She barely pushed the handle down into the soil and the handle was well and truely stained (see photo)
So since the watering in this case was rain, then it’s not down to nozzle incles settings ??? I do feel that the soil is very muddy, so it really holds the water. Is there some setting which I can adjust which will balance better with the slowdown of drainage.
The only thing is the Crop Coefficient. You’re in an ideal position to evaluate it, in fact: You know your zones are saturated, and no watering or rain has occurred for some days. And the graph seems to indicate it will water about every 4 days, based on the current temperature and weather conditions.
And if your zone settings are substantially the same, then they will all have the same graph. So, FOR THOSE ZONES STILL QUITE WET, you might lower the Crop Coefficient, maybe by 20% in this case. I say for the wet zones, because you might do the same test in other zones, and find some are not as wet, due to downhill drainage from one zone to another, etc.
Either way, try to keep an eye on the vegetation to make sure you’re not reducing the Kc and drying out the zone too much.
Every zone is flat. Some zones are slightly more shaded than others. There is rain this weekend and then more projected next weekend, so we are saving a fortune, given that each night of watering appears to use about 25m3 if all zones operate.
Of course, the consequence of the rain means that I still haven’t managed to get 3 or 5 min tests done.
Not that unusual. We had lots of rain yesterday (over 1"), with another 0.14" today, so my zone is at 107%. In 2 days it will be at 40%, and will water again on the 3rd day. And our weather has been that hot (yet).
What sort of temperatures were you getting. Our’s appear to be heading for the 23 - 25 Deg C range for the coming week. Would you have any idea as to potentially how long a 110% soil moisture content should last ?
We’ve decided to buy one of those $10 batteryless soil moisture meters off Amazon to be a bit more scientific about measuring the moisture level
Our temperatures in South Carolina have been about 80 degrees on average for highs. For the current week, Rachio shows the following daily Crop Evapotranspiration values:
0.19, 0.13, 0.14, 0.08, 0.15, 0.17, 0.18 inches
Which means my grass needs a total of 1.04" per week, roughly 0.15" per day. My zone gets 0.51" of water each time it waters. So right now watering occurs every 0.51 / 0.15 = 3.4 days, so every 3-4 days.
110% won’t normally last more than a day. After all, if watering occurs say every 3.4 days, then the moisture content would reduce about 30% a day.
I have a couple and haven’t found them useful. I’ve been unable to get any real correlation between the meters and Rachio’s moisture content.
Keep in mind, that 110% is technically a range from Allowed Depletion (standard set at 50%) up. So 0% on the moisture graph is actually matches the 50% allowed depletion (or whatever you have AD set at. Again, these are values based off some really fancy algorithms in Rachio that a couple people in the past (with systems dialed in) have found to be pretty darn accurate. In the link below, you can see that @gaustin used some really nice commercial equipment to show that when Rachio saw 0% moisture and 110% moisture, what that actually correlated to in soil moisture. Your soil is filled with air, soil, and water, so the only way to have a true 100% would be to measure under water…Your soil probe is going to show totally different percentages than Rachio.
