GPH calculated to inch

post by pjbakka on May 31, 2018

I have 12 sapling trees that required 1 inch of water per week. If using a 2gph emitter how long do I need to run it to get 1 inch of water to those plants. The drip line is hooked onto emitter and run direct to base of sapling so I don’t have a square footage I’m watering it’s directly to each tree.

post by tmcgahey on May 31, 2018

Just 1 emitter per tree? Going to need more than that as it grows, or you’ll be watering all day long…

post by pjbakka on Jun 1, 2018

Ok good to know going forward. How long will a 2 gph emitter take to water 1 inch though? I also want to divide that 1 inch over the course of a week. So watering every 3rd day.

post by Kubisuro on Jun 1, 2018

I’d start with 1ft square (for canopy coverage) for a saplings as your “coverage” area to calculate in/hr. Increase that at least once a year as your saplings grow — I measure the radius from the trunk to the drip line and calculate the area. I personally set Iro in Flex Daily to a single tree instead of averaging it across the zone. See this thread and included spreadsheet on how to calculate inches per hour — since these are saplings you may consider reducing the root depth a bit and deepen it as they grow. However for my orchard, I do water to 24” depth for new trees just to keep things simple and encourage deep root growth.

With 2 GPH emitters, 1ft2 canopy that you‘re targeting watering for, it should come out to ~1in/hr but please don‘t take my word for it — definitely understand how the spreadsheet and conversion formula works.

Another resource for Flex Daily: