Common mistakes to avoid The following list is designed to help you familiarize yourself with some of the most common mistakes made during design and/or installation of a drip irrigation system. Not enough emitters: One of the most common mistakes made is not using enough drip emitters. You need to ensure that the plant you are watering will have its entire root system watered. Large plants and/or pots may require many drip emitters or dripline. Try to avoid a situtaion where a plant is relying on only 1 emitter for all water. If the emitter clogs, the plant may die. Ideally, all plants would be able to draw water from at least two sources to protect against cloged emitters. This can be accomplished by using two or more emitters per plant or sharing emitters between plants. The exception to this rule would be small pots (12" or under). With small pots, usually 1 emitter is all that is practical but the clogging risk remains. Bad placement: Another mistake is to place the drip emitters too close together or too far apart. Drip emitters should be spaced evenly around the plant and kept at least six (6) inches from the base of the plant. This will help to avoid any fungal infections on the main plant stem. If your plant is on a hill, place the majority of emitters above the plant. Poor filtration: Use the correct filter for your drip system. Select the proper screen mesh for the water quality and type of emitters used. We recommend using a filter with a screen mesh of at least 155. Never operate a drip system without proper filtration, doing so is just asking for problems. Incorrect pressure: For a drip irrigation system to function properly it must be operated at the correct pressure. (PSI) If you try to put too many emitters on a line your pressure will fall below the operating minimum pressure and your system will fail. If you use an incorrect pressure regulator or none at all, your system will have too much pressure and not operate correctly. Improper zoning: "Zoning" refers to grouping large drip systems into "zones" of commonality. Usually, zones are grouped by plant type. Trees are separated from shrubs. Dry climate plants are separated from humid climate plants etc. If you have various soil types you can separate them into zones also. The main thing to remember is, after you get your system running, will you be able to water each plant according to its needs? If you put a large tree on the same line as a small shrub, one of them is probably going to be too dry or too wet. Wrong watering schedule: The key to this is, "trial-and-error". Don't just install your new drip system and walk away, trusting that your plants will make it. A drip system is not a "hands off" method of watering. A drip system is a "less hands on than if you had to stand there all summer with a hose" method of watering. You still need to check on the system periodically to ensure that it is working. Adjust the run times for the season. If you have a few days coming up that are 105 degrees, you may want to run the system a little longer. Likewise, if it is unusually cold for the season you may want to shorten the run times to keep from drowning your plants. The key is to watch your plants and pay attention to their needs.
Always Use a Filter
You must use a filter with the proper size screen: To protect the small orifices of the drippers and microsprinklers you must install a filter at the beginning of the system. For most installations a screen mesh of 150 or above is recommended to keep your drippers from clogging .
Use a Pressure Reducer
You should use a pressure reducer: A drip system may leak unless you use a pressure reducer to ensure that your drip line maintains a constant pressure.The only exception to this is if your water source is non-pressurized such as a pond, rain barrel or cistern.
Know Your Threads
Threaded parts can be either Hose thread or Pipe thread: Some drip irrigation parts such as pressure regulator, backflow preventer, filter and others have threads. Most have the option of either pipe thread (PT) or hose thread (HT) and within the thread type you will have the option of female or male. FPT = Female Pipe Thread MPT = Male Pipe Thread FHT = Female Hose Thread MHT = Male Hose ThreadThread types have these acronyms: NPT = National Pipe Thread (this encompasses all sizes and genders) GHT = Garden Hose Thread (always 3/4", can be male or female) You cannot mix thread type unless you use an adapter first. If you mix thread types your system will leak, guaranteed. To create a leak free connection, GHT and NPT threads differ. GHT creates a water tight seal by applying pressure against a washer that is seated in the female part of the fitting. NPT creates a water tight seal by tightly sealing the male and female threads. Therefore, remember these two rules. You never use Teflon tape or pipe cement on GHT. Hand tightening is usually sufficient for GHT. You always use Teflon tape or pipe cement on NPT. NPT threads usually require more than hand tightening to seal properly.
Drip Tubing Sizes
Drip tubing comes in different sizes: SPECIAL NOTE: If you plan on purchasing all of your 1/2" poly tubing and fittings from Drip Depot then the rest of this article does not apply to you since all 1/2" tubing and fittings carried by Drip Depot are compatible. Unfortunately, drip tubing (also referred to as "poly tubing" because it is made from polyethylene) comes in different sizes and the different sizes are not compatible unless you use adapters. Poly tubing is measured in Inside Diameter (ID) and Outside Diameter (OD). Many times you will hear poly tubing referred to as 1/2" poly, 3/4" poly, 5/8" poly etc. These designations are generalities. In fact, 1/2" poly tubing can reffer to 3 different sizes, none of which are compatible with some fittings. Drip Depot carries poly tubing in one size only which is .600" inside diameter (D) and .700" outside diameter (OD). If you purchase all of your items from Drip Depot you can be certain that they will all be compatible. However, If you have an existing drip system and you want to add to it, you'll need to ensure that you get the proper size tubing and parts or get the correct reducing coupling to mate the systems.1/4" tubing (vinyl and poly) also comes in different sizes however, even different sizes of 1/4" tubing will usually work together.
Tips on Drip Irrigation
Helpful Hints If this is the first time you are installing a drip or micro sprinkler system, we recommend trying one of our drip irrigation kits. Each kit contains everything you will need to install a working drip irrigation system. All of the parts are available separately to add on later. The ideal working pressure for your drip or micro sprinkler system is 25 psi, but most systems will operate fine between 15 and 30 psi. Use a pressure regulator to reduce high pressure. Install pressure regulator after your filter. Allowing the 1/2" poly tube to sit in the sun will make it easier to work with. If you are having difficulty inserting your 1/4" barbs into 1/4" micro tube, dipping the micro tube into warm water will make it more pliable. You can also heat the ends of the tubing using a hair dryer.