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How To Calculate The Flow Rate Of My Hose Spigot

I’m gonna take a few minutes here and talk about flow-rate with you. If you put too many sprinkler-heads or drip emitters on your irrigation system, you may have a problem – a dead plant problem. Your irrigation system must have a high enough flow rate to properly power those emitters.

Chances are if you bought a small kit your external hose spigot on a normal residential house or well is going to work just fine. However, if you’re building a system that’s a bit sizableโ€” you should measure your flow rate just to be sure. I’m gonna show you how to do thatโ€” with the timer, a calculator, and a five-gallon bucket. Alfred Castillo here the Sprinkler Warehouse Pro.

Let’s Get Started With A Timer And A Bucket

If youโ€™ve got a smartphone, you’ve already got the timer and calculator. So, put your bucket under your hose spigot. And open it up all the way. And start your timer.

Forty-two seconds!

Not bad. Now onto the math.

Here’s The Formula To Calculate Flow Rate

The number of gallons divided by the number of seconds to fill the bucket equals gallons per second. Gallons per second times 3,600 equals gallons per hour.

My bucket filled up in 42 seconds.

Iโ€™ll divide 5 gallons by 42. And I get 0.119.

Now multiply 0.119 by 3,600. And I get 428.

428 gallons per hour.

But we’re not done yet!

Flow rate can still be limited by the tubing we’re using in our drip system. Half-inch poly tubing, which is often used for your mainline, is limited to 220 gallons per hour. While three-quarters-inch poly tubing has a maximum flow rate of about 480 gallons per hour. If I run a half-inch mainline; that means I won’t be accessing the full availability of 428 gallons per hour. If I need a greater flow rate than my capacity will allow; I’ll need to establish zones. Or I might want to establish zones if I have plants with vastly different watering needs. For instance, if some of my plants need watering daily while others only need once a week.

You can find out more in our video โ€œDrip System Zones.โ€

Remember Sprinkler Warehouse Has Everything For Your Irrigation Needs

We’re here to help see that your trees, lawn, flowerbeds, and gardens, are lush and beautiful. If you have any questions about our products, chat with one of our amazing customer service agents at They really know their stuff. And they’ll get you squared away. Please subscribe to our YouTube channel to get the most out of our user-friendly shop online. For Sprinkler Warehouse, I’m Alfred Castillo your Sprinkler Warehouse Pro.