How It Works
Summary: Basic watering kits are comprised of 3/8" (CTS) straight tubing (4' to 12' long) with small (1/8") holes about 18" apart, and push-to-connect fittings to create a "garden layout".
This Sheet: Explanation why a low water rate, less than one (1) gallon per hour (GPH), makes this water system work as well as it does.
Low Pressure
As water starts to flow into the tubing, imagine it flowing like a stream along the bottom of a tube.
This flow will continue until the end of the tube.
Once the stream reaches the end of the tubing, the water will start to slowly fill the tubing.
Soon the water will fill up above the holes in the tubes. Due to cohesion, the water does not immediately flow out of the holes—the water will continue to fill the tube.
When water/air compression and pressure equalize the water will flow out the holes, flowing evenly and consistently throughout.
Tubing Layout
While a garden layout is the usual usage, any layout will work the same, as will be apparent after comparing these two seeminly different layouts.
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| Layout G | Layout Z |
A typical vegetable garden layout, with six, 10' tubes spaced 12" apart (50 ft. sq), with the tube holes about 18" apart (total of 36). Such a layout will fill and start evenly distributing water in a few minutes.
Just a few minutes more and the garden is saturating with water.
The seemingly much different layout it turns out has about the same overall tubing length and, more importantly, has the same square footage and identical water coverage, though the "time to fill" will be longer.
At saturation the two layouts spread water identically.
Conclusion
The result is a water flow that is even and consistent throughout the entire length of the tubing, with zero water loss and all water slowly going only to where it is wanted.