Run 1 program or 2?

[TheRealJash]

Hey guys. I'm a newbie so I apologize if this question has been beaten to death! Currently I have a 7 zone irrigation system and when it was installed it was programmed to run 20 minutes in each zone. I'm curious, do you guys recommend running 2 programs and cutting the time in half? Example: Run each zone for 10 minutes (give the ground time to absorb the water) then set the system to run right away again for another 10 minutes in each zone? Thanks in advance!

[chrismar]

Some controllers have this functionality built in. Look in your manual for run/soak times.

The mentality behind it is to reduce the amount of runoff. If you know how long it takes for X amount of water to infiltrate your soil you can certainly program your controller as you describe above, that is, if it doesn't have it built in.

[bmelz]

It really depends on your lawn and how well it absorbs the water. You definitely do not want the water to pool up. I would just sit there and watch it a couple times to get an idea of how much water you can put down before it starts to pool up.

[g-man]

The answer is, it depends on your soil and irrigation design. First, the main recommendation is not to water every day for a short time. The guideline is one in of water (rain or irrigation) per week. 20 minutes per zone seems short. The best thing is to figure out how much you have to run each zone to get one in of water on the lawn. To do this you will need rain gauges. You could buy some from amazon or use tuna cans. The tuna cans are close enough to an inch. Set the cans in the zone and run the zone (or zones) that water that area and determine how long it takes to fill the can. It is likely more than an hour. Each area could be different time depending on the irrigation design, so test them all.

Now comes the next part. Lets say it takes 2 hours per zone to get an inch. Set the program to 2 hour and next week run the cycle, but this time look for runoff. This means that the soil is not absorbing the water and it is pooling and following the grading. If no runoff, then you are good to go. If runoff, then i would split the total time in half and wait 2hrs in between zones and recheck next week. If still seeing runoff, then split the time into 1/3. More than that means that your soil needs help. Take a soil sample and send it to logans lab (per the soil forum post).

[TheRealJash]

Thanks a lot for your input guys! Let the beginning of "500 dollar water bill season" begin!