by Stuart Spaulding —
CLIA Certified Landscape Irrigation Auditor Training & Communications Manager at DIG Corp.

Whether you want to grow plants as a hobby or you do this as a profession, you have to be knowledgeable about the irrigation system to be successful in your endeavors. There are many different ways for you to water your plants. Of course, surface irrigation is the most widely-known and the easiest one for most. However, it is not the most efficient way of watering the plants and fields. As of the moment, there is no system better than drip irrigation for how efficient it is.

Understanding Drip Irrigation

When you grow plants, you have to know their needs. Their basic needs include water, light, and air. And while any irrigation system can be used to water plants, it is the efficiencies of these systems that make one better than the other. In drip irrigation, you have to use emitters, tubing, pipes, and valves to make water reach the plants. As you can tell from the name, the water drips to the plants in this type of system. You have to create a network of pipes and tubes in the fields to make sure that water reaches every plant.

The main idea here is to water the plants by sending water directly to the roots. It can be done on the surface or by using pipes buried under the ground to water the plants. The reason why this type of irrigation system has become so popular in the recent years is that of its sustainability and efficiency. Water the plants using sprinklers or using any conventional methods results in the consumption and wastage of a lot of water. On the other hand, in drip irrigation, there is no wasted water as it reaches the roots of the plants directly. It is even safe from the evaporation process.

Drip Irrigation imperative in areas where water is scarce. The best thing about this system is that it can be used commercially as well as residentially.

The Main Components of Drip Irrigation System

Here are the main components of a drip irrigation system.

Water Line

Of course, it is all about water, and so there needs to be the main water line that feeds the tubing.

Pressure Controllers

They are also known as pressure regulators and reducers. The success of a drip irrigation system lies in using water at very low pressures. This is where the pressure regulators come in.

Fitting Equipment

A variety of barbed and compression fittings are available and provide many options for constructing the systems. This equipment comprises a variety of accessories including ells, adapters, couplings, tees, etc. These accessories connect the main waterline to the system and driplines and micro tubing.

Drip Tubing

Drip tubing is the part of the system that provides water to the plants. It is the drip tubes that have emitters installed on them. The emitters on the drip tubes can be installed on regular or irregular intervals. You have to purchase your drip tubing based on your needs. If your plants are not located at regular intervals, you will have to go with a manual tubing solution.

Since drip tubes are the most important part of the system, here is some detailed information about them.

Detailed Information about Drip Tubing

You have to know at this point that you can’t successfully install an irrigation system unless you are sure of your requirements. There are different tubing sizes available, and you have to pick the right one for your needs. Picking the wrong sizes can mean that you will not be able to connect the tubing to your irrigation system.

  • The Basics

The first and foremost factor to consider when you are out to buy drip irrigation tubing is the size of your drip tubes. When it comes to buying the tubing, you have to consider the size regarding ID (inside diameter) and OD (outside diameter). Both the ½” and ¼” tubing are poly tubing having more sub-sizes within these categories. It is important o know these sizes to pick the right fittings for your irrigation system. Sometimes, you can have troubles in measuring the outside diameter of tubing you need. In that particular case, you have the universal fitting options available too.

It is important to note here that the inside diameter of the tubing also gives you an idea of how much water (water pressure) can pass through it at any given moment. The bigger the inner diameter, the more water pressure the tubing can handle.

  • Poly Tubing

Poly tubing is also referred to as polyethylene tubing or blank irrigation tubing. There are many different lengths and sizes this type of tubing is available. The position of poly tubing in the irrigation system is to act as the main tube or the sub-lateral to carry water to the micro tubing. An entire irrigation system consists of both types of tubing, i.e., micro and poly tubing.  This type of tubing comes in the category of ½” tubing wherein it has many different qualities that make it the indispensable component of any drip irrigation system. Here are the different ½” tubing size variations available.

½” Tubing Sizes

  • .520” ID x .620” OD (requires compression fittings that have green insert)
  • .600” ID x .700” OD (requires compression fittings that have black insert)
  • .615” ID x .710” OD (requires compression fittings that have blue insert)

You should note here that compression fittings with blue insert can be used with .620” ID x .710” OD as well. Furthermore, you can also find an additional configuration:

  • .570” ID x .670” OD (requires compression fittings that have brown insert)


There are some other polyethylene tubing sizes available as well other than these most popular ones. They are as under:

  • 1/8-inch

.125” ID x .187” OD

  • ¼-inch

.170” ID x .250” OD

  • 3⁄8-inch

.375” ID x .500” OD

  • ¾-inch

.820” ID x .940” OD

  • 1-inch

060”ID x 1.200” OD

Make sure that you are aware of the many different sizes of tubing available before purchasing and starting your irrigation system.

  • Drip Tubing

Also called micro-tubing, this is the part of your drip irrigation system that extrudes from the main poly tubing and extends forward to the plants. The water comes from the main line into the poly tubing, and from there to the drip tubing. The micro sprinklers and emitters are attached to this part of the drip tubing network. However, irrigation systems that are very small in size and need to provide very little water to the plants can use drip tubing or micro-tubing as the main supply line too. This type of tubing is also available in many different sizes.

Keep in mind that the ½” option is available in drip tubing as well. However, there is a slight difference in the internal and external diameter of this part of the tubing from the same size tubing in the ½ inch category.

  • ½” Inch

.570 ID x .670” OD

.550 ID x .640” OD

  • ¼ Inch

.170” ID x .240 OD

When you are looking for drip tubing in the market, you will find that it is commonly available in black color. The resistance to sunlight is great in drip tubing. You can choose from the many different lengths that are available starting from only a 100-ft to 1,000-ft.

Now, from the information given above you can tell how the water moves in the drip tubing irrigation system, e.g. it flows from the main water line into the poly tubing section, which is a bit bigger allowing for more water to pass. From the ½-inch tubing, the water has to travel into drip tubing and from there into the plant roots.

Deciding the Type of Tubing, You Will Need

One of the biggest dilemmas for those who are doing drip irrigation tubing for the first time is to know which size of the tubing they will have to get. As mentioned above, the needs can vary from person to person and the size of the irrigation system that one needs. In its simplest form, an irrigation system might not even need different types of tubing. An arrangement of the most basic form of irrigation system will look something like this.

Valve – Backflow Preventer – Pressure Regulator – Filter – Tubing Adapter – Drip Tubing – Emitters – End Cap

The water will flow from left to right, i.e., you turn on the valve; the water goes from backflow preventer to the end cap.

A few things to know while buying tubing for your irrigation system is that ½” tubing does not have to be that size, i.e., the size will not be exactly ½”. Furthermore, the .700 OD x .600 ID remains one of the most commonly used sizes in most irrigation systems. The size that looks most like ½” tubing is the .580. Another important consideration in addition to the type of tubing is emitters and the amount of water that flows through them at any given moment. As a general rule of irrigation, keep your flow rates slower if the soil you are using is dense.