There are many choices to make when it comes to drip irrigation drippers (sometimes called emitters). To choose the best one for your project, you have to take into account several factors. These factors include but are not limited to pressure compensating (pc) vs. non pressure compensating, dirty or hard water, elevation changes, and varying water requirements between plants. In this guide we will discuss each of these factors as well as several other considerations in more detail.
A pressure compensating dripper will deliver the same amount of water to each plant regardless of changes in pressure throughout the drip irrigation system. A non pressure compensating dripper will not compensate for the pressure change, and thus not all your plants will receive the same amount of water.
What might cause a rise or drop in pressure in a drip irrigation system? Very long runs of tubing at or above the gallon per hour capacity for that tubing size and/or changes in elevation. If your system is using long runs of tubing or is installed over terrain that has elevation changes, then we recommend a pressure-compensating drip emitter.
If your water is coming from a well, pond, rain barrel, or other source that collects debris, then we strongly recommend a cleanable dripper. This recommendation also goes for anyone that has hard water and sees deposits build up. Cleanable drippers can be opened up and cleaned. If you were to use a dripper that was not cleanable, and it were to get clogged, you would have to replace the entire dripper, since there is no way to clean it. Cleanable drippers allow for the head of the dripper to be unscrewed from the base of the dripper so that the orifice can be cleaned of any scale or debris that is blocking the flow of water.
Recommended Drippers: Cleanable Economy Dripper, Flag Dripper, Toro Cleanable Dripper, Turbo SC Cleanable Dripper
Another great option for less-than-perfect water is the Bowsmith Non-Stop Dripper.
Slopes and elevation changes can change the pressure within a drip irrigation system. This can alter the amount of water that is emitted from each dripper in a system. If this is not a concern for you, then you can use any dripper you like. However, if you are watering on a slope and you wish for all the plants in the system to receive the same amount of water, then we recommend using a pressure-compensating dripper. See our full selection here.
Recommended Drippers: CETA Cleanable PC Dripper, iDrop PC Emitter, Pressure Compensating Dripper with Barbed Outlet
For anyone looking to place emitters directly into PVC, a threaded emitter is needed. The barbed emitters will not connect directly to PVC. Our threaded emitters and threaded ¼' fittings are all on 10-32 threads. To use these, you would simply pre-tap your PVC with the appropriate sized drill tap bit and screw in the emitter or fitting. If you want to use a barbed dripper with PVC, you can use our 1/4" Barb Adapter x 10-32 Thread. You would pre-tap the PVC, screw in the threads, and then attach a length of micro-tubing and insert the barbed dripper at the end of the micro-tubing.
Recommended Drippers: Adjustable Dripper on Threads, Mini Bubbler on Threads orVortex Sprayer on Threads
Any emitter could work for this application. However, there are a few things to consider. First, it is critical to have the emitter centered over the basket. For this we recommend using a rigid riser instead of micro-tubing (micro-tubing can curl and place the dripper to the side of the basket). To insert an emitter into a rigid riser, a threaded dripper is needed, so a dripper on 10-32 threads is preferred. Secondly, hanging baskets drain very quickly, so a dripper that can emit a lot of water quickly is needed. We have found the perfect dripper to be our adjustable dripper on 10/32 threads. As a bonus, the dripper can be adjusted all the way closed, if needed.
Recommended Dripper: 360 Adjustable Dripper on Threads
Watering schedules for plants in containers will be different from those for plants in the ground. The soil most often used in containers is potting soil, and potting soil has little to no capillary action. What this means is that there is very little horizontal movement of the water from the top to the bottom of the container. In addition, plant roots in containers dry out much faster than plant roots that are planted in the ground. We have found that a typical watering schedule for containers will look something like 2'4 times per day for 1'2 minutes each time.
For more information, please visit Lfsprrain.
When choosing an emitter for your containers, you will want to take the above information into consideration. You can use any dripper that we sell, but depending on your choice of emitter, you may need to add additional drippers to ensure good water coverage. You may also need to add a stake to anchor the emitters in place so they do not fall out of the pot.
The main goal in choosing an emitter is to get good root zone coverage. This is true regardless of where the plant is planted. As was mentioned previously, potting soil has poor capillary action, so you will only get about a 6' wet pattern from each drip point. If your pot is small, then one button dripper is great, but if your pot is large, you will need to determine how many drip points you will need for good root coverage.
We sell drip spikes that have a dripper built into the stake, which can translate into real-time savings if you have a lot of pots to irrigate. For a container that is 6'8 inches, one dripper should work. For larger pots you may need to place more than one dripper in the container to adequately water the plant. If the pot is very large and has a water hungry-plant inside, then we would recommend one of our adjustable drippers on a stake.
Recommended Drippers: PC Dripper on Stake, Adjustable Dripper on 6" Stake, or Adjustable Mini Bubbler on 6" Stake
One of the largest challenges in setting up a drip irrigation system is balancing the watering requirements of a variety of plants. This can be done one of two ways: you can either create separate watering zones for like plants, or you can select different drip emitters based on the plant's watering requirements for an area.
For example, let's say you have two plants on the same watering line; one plant requires moderately moist soil, and the other plant requires consistent moisture. In this case, we might recommend an emitter such as a .5 GPH (gallons per hour) button dripper for the first plant and an adjustable dripper for the second plant. The button dripper will only deliver the regulated amount, in this case a half a gallon per hour, but the adjustable dripper, depending on the model chosen, could deliver up to 20 GPH. These drippers are fully adjustable by simply twisting the top of the dripper from closed to fully opened and all points in between.
Adjustable drippers come in maximum flow rates of 10 and 20 GPH. One word of caution here is that these do eat up a lot of water, so try to use them sparingly, as too many may overtax your system. The end result is that by matching the dripper to the plant's watering requirements, you are able to better water plants with different watering requirements all on the same line.
Buying Guide: Driptape, Dripline, or Poly Tubing W/ Emitters
Selecting the proper drip device for your use depends on a couple of variables, each equally important. The three types of products we sell for drip systems are driptape, dripline and blank poly tubing with emitters added as needed. Each is capable of different flow rates and emitter spacings, so it can be adapted to fit many configurations. Preinstalled emitters can be 4', 6', 8', or 12' apart on driptape and 12', 24', 36', or 48' apart on dripline. We do not install emitters on poly tubing, but we do sell them for customers to install.
The first factor that will decide which product to use is the flow rate needed. Knowing how much water your plants need is crucial. This will depend on the overall water needs of your crop or plants, as well as the type of soil they are in. Clay is slow to absorb water and would require a lower flow drip tape, while sand absorbs water quickly, so a higher flow rate is possible. Drip tape will be the lowest flow choice, ranging from a .09GPH emitter to a .27GPH emitter. Dripline is capable of a higher flow rate of .5GPH to 1GPH. Poly tubing can be customized with any compatible emitter. This allows you to tailor the flow and the emitter layout for more custom applications. Self-installed emitter flows can be anywhere from .5GPH to 18GPH. The flow needed will dictate the entire system. Lines and connections need to be sized to accommodate that flow.
The second factor is life span needed. Drip tape has different thicknesses measured in thousandths of an inch or 'mil'. The higher the number the thicker the wall of the tape. A thicker tape will last longer than a thinner one. Driptape is best suited to crops that are more seasonal as it is cheaper per foot and most users will discard after one use. The most common thickness is 8mil tape, that is a great starting point for new users. If you get unexpected leaks caused by animals or workers, then trying a thicker tape next year is recommended. If you have success with 8mil then using a thinner tape next season may be possible to save money. If you need a longer lifespan for a crop that grows over multiple years like orchards or vineyards, dripline would be a great alternative to driptape. Dripline is like blank poly tubing, but with pre-installed emitters. Like poly tubing, it can last on average about ten years before any noticeable degradation. For seasonal crops use driptape, for year-round or perennial crops dripline or poly tubing is best.
The third factor is the diameter of tubing. The most common size is 5/8'. It will be easiest to find fittings in this size, whether it is for driptape, dripline, or poly tubing. The reason to go to a larger diameter driptape would be if there is too much pressure loss from row length using 5/8'. A lot of times you can use a lower flow on 5/8' and still have acceptable pressure loss, granted you will need to run the system slightly longer. If you are unable to reduce the flow, then going larger is needed. The next size for driptape is 7/8'. It can have maximum row of ft at .22gpm, whereas the same flow in 5/8' will max out at 835ft. For rows longer than that you may need to use blank poly tubing like ¾" or 1' and install emitters as needed. Use our pressure loss calculator to decide line size needed, based on flow rate and length of run.
If you want to learn more, please visit our website Pressure Compensating Drip Tape.