This has been confusing me too. I’m coming at this a little differently, with a little less math, but I’m wondering if I’m starting to see a little of what is going on.
@plainsane , did you by any chance tweak your duration times on the previous version of the software? The comment
makes me think that you did.
Here’s what I’m seeing after playing around quite a bit this morning.
My zone 5 and zone 6 are set up identically. Last year I had problems with them getting too much water. They are in an area of my yard in mostly shade that just does not drain well. And the zones overlap. So last year I did a duration tweak of 65%. Under the old software, that tweak made the system THINK it was still putting down the .61 inches which was supposed to have a watering time of 45 minutes. But I was only watering for 30 minutes.
Here’s the weird thing I’m seeing now. I think that my 65% duration tweak from last year is still in place, and I can’t get it back to 100%. I set up a test phantom zone (zone 13) IDENTICAL to my zone 5, and it calculates out that it will water for 45 minutes. Went back to my zone 5 and changed characteristics (I was playing with root depth) to make sure I could see the duration changes. But when I make my zone 5 and my zone 13 exactly identical again, zone 5 wants to water for 29 minutes and zone 13 for 45 minutes. That 29 minutes is 65% of the 45 minutes. Which seems to me that it’s keeping my previous tweak (only it no longers tell me that I had tweaked it or what that tweak was).
Luckily, I keep track of all my zone settings (and changes) so I at least know what duration tweaks I had set.
But had I not recorded those tweak percentages, I wouldn’t now know how to change the durations to get them to what the schedule recommends. @plainsane, I think this is part of what is throwing you off.
And I did actually like that tweaking the duration time was a way to shorten watering time without getting into all the increase/decrease frequency/watering amount since I was having such a hard time with this area of my lawn.