The other reason low pressures are necessary in a drip irrigation system is that we want to deliver water to the roots very slowly so the water stays at the roots and doesn't cause overflow.

It will take about an hour for one gallon of water to flow to the roots in a typical drip system.

So far we have filtered the water, reduced the pressure and delivered it to the greenhouse. Next, we route 1/2" PE tubing so that it is within two feet of every plant or plant container. In a 8' x 10' hobby greenhouse, we may place the PE tubing around the perimeter of the greenhouse or along the edges of the benches.

In a large greenhouse with rows and plants rooted in the ground, we may lay 1/2" PE tubing down each row if the rows are wide or between rows if they are narrow. If the tubing is placed next to the crown of each plant, we can simply add a dripper to the tubing at each plant and we are done.

A special punch is used to cut a small hole in the 1/2" tubing and the barbed end of each dripper is pushed into the tubing until it seats with a click.