How to tune up your irrigation system

Keeping your irrigation system working properly is very important in order to conserve water and money. In order to keep your irrigation system working at its maximum efficiency there are many different tips and words of advice to follow. Before explaining each tip that can maximize your irrigation system potential, there are some terms that will be helpful if understood.

Useful Sprinkler System Terms You Should Know:

Spray-type sprinklers, better known as sprays, create a fan-shaped spray pattern, much like a shower nozzle spray.
Rotor-type sprinklers, or rotors, that are often used for very large areas and have one or more streams of water that rotate over the landscape.
valve circuit, or valve zone, which is a group of sprinklers that are all turned on and off by the same valve. A sprinkler system must be divided up into separate zones since there is typically not enough water pressure to run all the areas of your yard at one time. Plus dividing the yard into common areas allows you to have more control over how much water you apply to each area. Examples of how a typical yard is divided into zones is front lawn, back lawn, front flower beds, back flower beds, left side of house, right side of house, parking strip, and down the edge of the driveway.

A well-designed and well-functioning system should apply water uniformly over your plants. It should work so that each plant’s needs are met, as well as meeting the needs for each type of soil. It may be easy to detect some problems, including broken nozzles, clogged or blocked ducts, or geysers shooting up from the nozzles, instead of spraying as usual. Or it may be as simple as adjusting the nozzle or spray level to make sure areas that don’t need water aren’t getting them, like sidewalks, streets, etc. However, there are also problems that may not be quite so easily noticeable. By manually starting your system monthly, or using the “test” mode on your irrigation controllers, you can cycle through each zone and make sure they are working properly.

Below is a list of some of the problems you should be looking for:

Spray heads or rotor heads that are too low. If the heads are too low they will not pop up over the top of the grass and spray a proper pattern. The grass can intercept the spray pattern and cause the spray to fall short or cause the area around the head to flood while the area farther from the head to be dry. You will need to raise any head that is too low by digging it up and replacing the riser under the head with a taller riser. An easier method is to dig up the head and unscrew it from the old riser and replace the riser with a Hunter pre-made swing joint.

Spray heads or rotors that are out of adjustment which causes them to spray areas that should not be watered (house, driveway, sidewalk) or causes them to spray too far or too short. Any spray or rotor out of adjustment should be adjusted by following the adjustment directions for the type and brand of head you have.

Zone valves that are leaking by allowing water to puddle around the lowest spray heads or rotor heads. If the valve does not close all the way it will allow water to leak by like a dripping faucet. The water will travel in the pipe to the lowest sprinkler heads on the zone and leak out the heads slowly causing a puddle or constant wet spot around the heads. This is a common problem after the valves have become old. The way to fix this problem is to locate the valve for the zone and replace it either by cutting it out and replacing it or by buying the exact model valve and using the top and internal parts from the new valve to replace the old valve parts (diaphragm and solenoid).

Zone valves that either will not turn on or will not shut off. This is common with valves once they get old. The way to fix this problem is to locate the valve for the zone and replace it either by cutting it out and replacing it or by buying the exact model valve and using the top and internal parts from the new valve to replace the old valve parts (diaphragm and solenoid).

Controller or timer that will not work properly. If the controller does not turn on either it is not getting electricity or it needs to be replaced. If the controller comes on but it blows a fuse while trying to water an area of the yard or it indicates that a particular zone has a problem and keeps skipping that zone, you will need to determine if you have a zone valve that needs replaced or if you have a wiring problem between the controller and the zone valve. Almost always it is the solenoid of the zone valve that needs replaced.

Additional Steps to Take While Tuning Up Your Sprinkler System:
Turn on each zone valve, one at a time to inspect the zone for problems. If you have above ground zone valves, carefully inspect the irrigation control valves for leaks, drips, or puddles around the valves. If you see leaking valves you will need to replace them. If you have below ground valves, you can skip the valve inspection if you do not know where they are located. Below ground valves typically do not leak around the valve, they tend to have problems like not turning on or shutting off or not shutting completely which is indicated by water puddling around the lowest heads on the zone. Some people say that you may be able to fix leaking valves by opening them up and cleaning the diaphragm, which will rid them of debris. I strongly suggest you replace the top of the valve (solenoid, diaphragm, and valve top) using the parts from a new valve of the same brand and model. If you are going to take the time to locate and open the valve, you should replace the parts since they are inexpensive. Cleaning the parts of a valve does not repair a deformed diaphragm or weak solenoid which is typically the cause of a leaky valve.

With spray-type sprinklers, you can easily remove the nozzle from the head and clean the screen under the nozzle by using a bent paperclip to help remove the screen. An old toothbrush does a great job cleaning the filter as well. Check the nozzles and make sure there is no debris blocking them. If you have any doubts about a nozzle, the best option is to replace it. Rotor-type sprinklers also have a filter and screen that can be cleaned, although depending upon the type of rotor, a special tool may be required. It can be a bit trickier to successfully clean rotors without getting additional debris into them, so unless you are absolutely certain they need to be cleaned, you may not want to even try. Rotor screens typically only need cleaned when you are using dirty water (ponds, lakes, sandy wells) as your water supply. If you are using the water from the city main, you should not really ever have to clean a rotor screen.

It is also necessary to adjust the sprinklers to make sure only the area needing water is being irrigated. All too often areas like sidewalks, streets, and decks are receiving water from the sprinkler systems, which is wasteful. In order to adjust spray sprinklers, you must turn the adjustment screw on the top of each spray nozzle. If mist is a problem, turn the screw clockwise. For rotor sprinklers, turn the radius adjustment screw clockwise just until it touches the water stream, followed by turning the screw counter-clockwise just until it is not touching the stream. This is the best position for the screw, and should be left there in most cases. It may take a few tries to find the best amount of adjustment for the screws. If the screw is too far into the water stream, it can cause dry areas, whereas if it is not in far enough, the pressure can be too great. You should always check the water pressure to make sure it is where it needs to be. Overgrown grass and shrubs can easily block areas of the sprinkler causing the water pressure to be compromised.

Adjustments to the direction of the spray a rotor or spray head may need to be corrected. All rotors have a fixed side that the rotation stops and a side that opens up for more rotation. An example is a Hunter rotor has the right side as the fixed side and it opens to the left for more of a rotation angle. Rain Bird has the left side as the fixed side and it opens to the right for more of a rotation angle. By digging a small area around the body of the sprinkler, you can easily adjust the position of the fixed side of rotation to line up with the boundary you are trying to water along and then adjust the head to spray more of a circle or less of a circle pattern by using the adjustment on the top of the rotor according to the manufacturer’s directions. Then by using the soil from which you dug, you can replace it to hold the head in place. Another way to realign the fixed stop of the rotor head is to turn the whole sprinkler body assembly and the fitting below it, left or right to the desired position. This may require temporary removal of the soil around the sprinkler to allow you to grip the sprinkler housing. Another way to reset the fixed side of the rotation arc is to unscrew the body cap counter clockwise and remove the internal assembly from the body. Once removed, rotate the nozzle turret to the fixed stop, screw the internal assembly back into the body with the nozzle aligned to the fixed side of the area you want irrigated. At this point you have realigned the fixed side arc stop, and you can adjust the opposite arc to an appropriate setting.

For spray heads, the direction of the spray pattern can be adjusted by grabbing the pop up shaft while it is spraying and rotate it to the correct direction. It will typically make a clicking or racheting sound but that is ok it is designed to sound like that as you forcefully rotate the pop up shaft. There may be times when there may be issues with the landscape that surrounds the sprinklers. Try to keep obstacles from obstructing your sprinkler heads, or consider retrofitting your sprinkler system in order to better fit the needs of its surroundings. Additionally, make sure that the heads are placed for “head to head” coverage. This means that the water from one head reaches all the way to the next sprinkler, with a 100% overlap in coverage. Another important step is to make sure your sprinkler heads are not tilted and are in the correct position. If the heads are leaning to the side, they need to be corrected so they are perpendicular to the ground. If they are not properly positioned, they can create dry spots and waste water. However, if the sprinkler is located on a steep hill, some tilting may be necessary to make sure all areas are reached. Common sense can be used to determine if this is necessary.

Each year you should check the battery to your system, and replace it at least every two years. Set the irrigation controller and make sure it is on the current date and time. If after a power outage the system does not go back to the correct time, the battery needs replaced. You can also set the days that your plants need to be watered, as well as the amount of water the plants should receive. A good rule of thumb is ¾ inch of water per irrigation cycle. This will moisten the soil around 8-9 inches deep, which encourages deeper rooting. This will in turn make the area more tolerant of droughts. In order to figure out how to maintain the system so that ¾ inch of water is dispensed, you will need to calibrate your system. This involves operating your system and using gauges to collect the water and measure it. By timing how long that takes, you can determine an average amount of time in which to set your system. Between 4-7 A.M. is the best time to water plants, because evaporation is reduced. If you want to figure a precise time, you can figure the run times from each zone of your system and subtract it from 7 A.M. This should give you a good idea of what time in the morning you should start your system. Don’t be afraid to only water on an as-needed basis however.

A rain sensor is a great way to avoid over-watering. These sensors can be easily installed in an area such as attached to the edge of a roof, pointed toward the sky. If installed properly, it will prevent your irrigation system from watering during or immediately after a heavy rain. You can adjust the sensor to stop irrigation after ½ inch of rain as well. Make sure to test it monthly to ensure it is working as well.

All of these maintenance procedures are very easy to detect. Regardless of the problem, it is important to take measures to quickly correct the issue so that you are making the best use of your irrigation system as possible. Keeping your system properly tuned will save you both time and money in the long run.