It works. It’s a little slow. But it clearly works. The flow rates above are per foot of 1/2″ dripline, hooked up to a water barrel. This particular dripline was rated for 1 gallon/foot/hour @ 25 PSI.
Background.
In my just-prior gardening post (G22-026), I found out just how easy it is to set up drip irrigation. In less than two hours, I set up drip irrigation for about 400 square feet of garden, divided into four beds.
As described in that post, I used 1/2″ drip line, connected to municipal (high-pressure) water. It was a snap to put together, and it works like a charm.
Blessed relief. Instead of hauling buckets of water, I turn on the tap.
My only regret is that I couldn’t use that with my existing rain barrels. The drip line is designed to deliver one gallon per foot per hour, at at pressure of 25 pounds per square inch (PSI). A system engineered for that pressure surely wasn’t going to work with the 1 PSI water pressure generated by a water barrel.
Or so I thought.
Experimental data. Accept no substitutes.
I’ve only been a serious gardener for three seasons now. But one of the first lessons I learned is that a lot of what gets passed off as advice for the home gardener is simply untested and untrue folklore.
In this blog, I’ve taken pains to test something before repeating it. The idea being that amateur science beats no science at all. Hence, I can tell you that (e.g.) poly sheeting is all-but-useless for frost protection, but mason jars provide excellent frost protection. Not because I read that somewhere, but because I both tested it and can explain why it’s so (Posts G22-005 through G22-008).
Today I’m testing whether I can use 1/2″ dripline for low-pressure (water-barrel) irrigation. To do that, I’m going to measure the output of that 1/2″ dripline when it’s hooked up to a water barrel.
Here’s the setup. That’s a water barrel on a cinder block, 50′ of 1/2″ dripline (rated for one gallon/foot/hour @ 25 PSI), and three Dixie cups. Plus some bricks to hold it all in place. Not shown is the kitchen measuring cup use to measure the output.
The experiment consisted of hooking the dripline up to the water barrel. Letting it drip for 15 minutes. Then measuring how much water was captured in Dixie cups placed at 1, 25, and 50 pipe-feet away from the water barrel.
The results are tabulated at the start of this posting. For me, that’s a more-than-adequate and more-than-adequately-uniform water output. Which means that all I need to do to convert my existing high-pressure irrigation system to low-pressure (water barrel) use is … hook it up to the water barrels and let it run all day. It will be easy enough to tell how much water I’ve put on the garden just by measuring the drop in the water level in the barrels.
Sometimes a (moving) picture is worth 1000 words. Click the link below to see a brief video clip showing how rapidly drops emerge from the dripline at 1 PSI. As soon as I saw this stream of drops, I knew this adequate for use in irrigating the garden.
