A distinction is made between two parts in spray sprinklers: the nozzle and the associated body. Nozzle and body can be combined as desired and are also sold separately in stores. The body is practically the sprinkler house from which the nozzle moves up. It essentially consists of a cylindrical casing and a riser housed in the casing, which ensures that the nozzle mounted on it rises a few inches above the earth’s surface from the casing buried in the ground. In addition, a thread is attached to the body with which it is connected to the water pipeline.

Cross reference: In a separate blog post you will find an overview of the nozzles available on the market

The bodies from Hunter, Rain Bird and Toro, i.e. the three major suppliers on the irrigation market, are presented below. All three offer several different bodies. Rain Bird and Hunter nozzles not only fit into all bodies of their own brand, but can also be used across manufacturers, i.e. Hunter nozzles in Rain Bird bodies and vice versa. This is also common practice in the world of irrigation. You should always follow the manufacturer’s recommendations whenever possible, as certain bodies are particularly suitable for certain nozzles, e.g. pressure-regulated bodies for rotating nozzles. Care must be taken when using non-Toro nozzles in Toro bodies or Toro nozzles in non-Toro bodies, as Toro nozzles can have both female and male thread connections, but only female nozzles can be used in the Rain Bird and Hunter bodies.

Some of the bodies are offered in a large number of different risers, i.e. with risers of different heights or as a shrub version (body without riser that cannot be lowered and remains on the surface). The type designations reflect the measurement of the riser: 02 stands 2 inches, 03 for 3 inches,  04 for 4 inches, 06 for 6 inches and 12 for 12 inches. All bodies presented here have a 1/2 inch internal thread connection.

Hunter PS Ultra, Rain Bird Uni-Spray and Toro LPS are marketed as entry-level models for private users. From my point of view, there is little reason to reach for them even as a private person: The models located above them are at least a touch better and much more varied and also cost practically the same. The only reasonable reason to use them is optical considerations, due to the slightly smaller outlet in the garden soil (see below under “Diameter visible from above”).

Hunter offers 4 different bodies: PS Ultra, Pro-Spray, PRS-30 and PRS-40.

PS Ultra is the entry-level body aimed at private users. It doesn’t have a quite as strong return spring as the other three models and only has a 2-year warranty instead of 5 years. Above all, it has – like the entry-level models of the two competitors – a smaller head diameter. So if you want to have the smallest possible outlet in the floor for optical reasons, you can achieve that with the PS Ultra.

On the other hand, there are significantly fewer riser variants for the PS Ultra than for the other models. The Pro-Spray and the PRS bodies are also more stable and therefore also well suited for places that are frequented by many people. According to Hunter, the PS Ultra is also not suitable for use with graywater, so it should not be used with water that comes from your own well. Some of the PS Ultra entry-level models are available on the market with already pre-installed nozzles (Hunter Pro nozzles with variable sector 8A, 10A, 12A, 15A, 17A or an SS-530 side strip nozzle). The main difference between the PRS bodies and the Pro-Spray is the built-in pressure regulation to 30 psi (PRS-30) or 40 psi (PRS-40).

Model comparison

Notes: Models with an integrated check valve have a “CV” in the type designation. The Hunter Eco-Rotator sprinkler available on the market is not a separate type of sprinkler, but a PS Ultra body with a 4 inches riser and pre-installed MP-Rotator nozzle.

Riser variants

The 4 models are available with the following different risers:

Rain Bird also has 4 bodies that are quite similar to the Hunter bodies: Uni-Spray, 1800 Series, RD1800 Series P30, RD1800 Series P45.

Uni-Spray is the entry-level model and therefore the counterpart to Hunter’s PS Ultra. Compared to the other three models, it has a significantly smaller head diameter and is only offered in a 4 inch riser version. It is often offered on the market in a ready-to-use combination with Rain Bird HE-VAN nozzles (8, 10, 12 or 15). The 1800 series is according to Rain Bird the best-selling spray body in the world. In addition to many other variants, it is also available in a pressure-regulated variant (recognizable by the type abbreviation “PRS” in the model name). The RD1800 is an even newer generation of models, which is specially designed for pressure regulation and also always contains a check valve. In the P30 variant, the pressure is regulated to 30 psi and in the P45 variant to 45 psi.

Model comparison

The RD1800 P30 and RD1800 P45 bodies can be purchased with an additional flow protection device as an option. With this, the sprinkler automatically registers when the nozzle has been removed from a pressurized sprinkler, e.g. due to vandalism or damage. Instead of allowing the water to spray out of the sprinkler in a fountain, the anti-flow device automatically ensures that the water flow is greatly reduced. As a result, less water is lost. This is probably not an issue for the typical private user, but is interesting for irrigated areas that are only inspected from time to time.

Riser variants

The 4 models are available with the following different risers:

Toro also offers roughly the same body models: Toro LPS, Toro 570Z, Toro 570ZPR.

At Toro, the entry-level body is called Toro LPS. It is often sold with the nozzles already installed (TVAN 8, 10, 12, 15 or 17). The Toro 570Z is the better body aimed at corporate customers. It is also sold to private customers in an identical form as Toro 570. The 570ZPR also has integrated pressure regulation. The 570 models are also optionally available with an additional flow protection device, which Toro calls “X-Flow”.

Model comparison

Riser variants

The 4 models are available with the following different risers:

Cover image: Hunter

This blog post gives an overview of the sprinkler nozzels available on the market, also known as spray nozzles or sprayers. Sprayers release the water like a shower head in a torrent in all directions to be sprinkled. Unlike the geared sprinklers, which rotate and only eject the water in a specific direction in a concentrated jet. These are covered in a separate blog post on rotating sprinkler performance data.

Spray nozzles are used for irrigating rather small areas and release a relatively large amount of water to the irrigated area in a short time, so they have a high precipitation rate. Accordingly, they must not be mixed in a sector with geared sprinklers, which have a significantly lower precipitation rate, and they can only irrigate a smaller area in a sector than would be the case with geared sprinklers. An exception here are the rotating nozzle sprinklers, which are a cross between spray sprinklers and rotating sprinklers. These do not emit the water in torrents, but rather in fine jets due to their rotating nozzle and therefore also have a significantly lower precipitation rate than standard sprayers.

Spray sprinklers use less water pressure than geared sprinklers. They are best used for irrigating small areas up to a maximum length of 13 to 16 feet with a floor plan with many curves or corners. The targeted sprinkling of individual trees or bushes that have a very high water requirement is also a possible using scenario.

Separation of nozzle and body

Unlike geared sprinklers, spray sprinklers have a separate nozzle and body. So you don’t buy the complete spray sprinkler, but a spray nozzle and a body and then combine these two to form the sprinkler. This has the advantage that, depending on the application scenario, you can combine a specific nozzle with a specific body that is best suited for the scenario. It is also practical to use, since if a nozzle is defective or if you are experimenting with different nozzle types or sizes, you only have to unscrew the nozzle from the body and screw in a new one instead of digging out the entire sprinkler and installing the new one.

The nozzle of the spray sprinkler differs significantly from the nozzle on the geared sprinkler: With geared sprinklers, most sprinklers come with entire nozzle sets, sometimes with up to 8 or more different nozzles. These are small nozzles measuring maybe 0.5 x 0.5 inches, of which you insert the desired one into the sprinkler riser. The nozzles of the nozzle sprinkler, on the other hand, are much larger and combined with a filter. You screw it on top of the riser of the body. You don’t buy a set of nozzles here either, but rather the exact nozzle you want, i.e. the type of nozzle you want with the desired throw range. The nozzle also makes up a larger part of the total sprinkler price for spray sprinklers compared to geared sprinklers. This is especially true for rotating nozzle sprinklers, where the nozzle, filter and rotating mechanism make up the actual sprinkler and the body accounts for the smaller part of the cost.

In the following, I will present the nozzles available on the market across all brands, together with their specific performance data. The matching bodies can be found in a separate blog post.

As a beginner, you can easily be overwhelmed when it comes to the nozzles, as there are a large number of different nozzles on offer, the difference between which is not immediately apparent at first glance and which also have different designations depending on the manufacturer.

Fixed arc nozzles

These nozzles spray a fixed part of a circle, 90 degrees, 180 degrees or 360 degrees, depending on the nozzle selected. A sector deviating from this cannot be irrigated. The advantage is that they reliably irrigate the predefined sector, you don’t have to set it up and it can’t be adjusted. In addition, the precipitation rates of the different sector sizes are coordinated within the same nozzle size, so that a uniform precipitation rate (MPR) can be achieved if only one nozzle size is used within an irrigation sector.

Variable arc nozzles

With these nozzles, the sector to be irrigated can be variably adjusted. You don’t need a nozzle that is tailored to the section of a circle, but you can flexibly define the section to be sprinkled on the nozzle, which gives you greater flexibility.

MPR nozzles

The precipitation rates of these nozzles are matched to one another, so that you always have the same precipitation rate (MPR) even when using different nozzle sizes. The Rain Bird and Toro nozzles work like the typical spray nozzles, so they have a comparatively high precipitation rate. The MPR nozzles are fixed sector nozzles. Depending on the sector size to be irrigated, you have to use the desired sector model, e.g. full circle, semicircle or quadrant. At Rain Bird, the MPR nozzles also have the same precipitation rate across sectors. At Toro, the same precipitation rate only applies to the different nozzle sizes with the same radius – and again only approximately.

Rotating nozzles (rotating nozzle sprinklers)

This is actually a separate sprinkler category that no longer has much in common with the original nozzler sprinkler (sprayer), but is more of a cross between a sprayer and a geared sprinkler. The nozzle head includes a rotation mechanism that ensures that the water is not released in a gush, but divided into jets and that the jets are released at different points parallel to the rotation of the nozzle head. As a result, the precipitation rate is significantly lower than with a conventional sprayer. With the amount of water available, you can irrigate a much larger area at the same time. In return, however, it has to be watered longer than with conventional nozzles.

The radius of the rotating nozzle sprinklers is also greater than that of conventional nozzle sprinklers and reaches up to 35 feet. All three rotating nozzle sprinklers presented automatically also provide MPR, i.e. they are also MPR nozzles at the same time. The nozzles are a cross between nozzles with a fixed arc and nozzles with a variable arc: Different nozzles are required to cover all sector sizes, these can be adjusted within a specified range, e.g. 90 to 210 degrees or 210 to 270 degrees. Only the nozzle to cover a full circle (360 degrees) is not adjustable. The Hunter MP Rotator is my top pick for a sprinkler.

Bubblers

Deliver water directly to the root area of the plant. This comes out with minimal pressure and hardly any throw distance directly at the nozzle or in the immediate vicinity of the nozzle and is released at close range to the ground surface. Depending on the model, this can be done either in surges in the form of an umbrella or divided into jets. Bubbler nozzles are used for watering individual trees or shrubs that require more water than the surrounding vegetation, or for watering very small areas.

In addition to the above, there are the following types of nozzles for special tasks:

Strip nozzles

Used for watering narrow, rectangular areas (lawn strips). Three different nozzles are always required to water a rectangle (nozzle in the left corner, nozzle in the right corner, nozzle in the middle).

Short radius and stream spray nozzles

Short-radius nozzles are nozzles with a short throw distance that is always the same, regardless of the water pressure, for watering in very small spaces. Stream spray nozzles divide the water jet into individual jets and have a lower precipitation rate compared to conventional spray nozzles.

You can find the right bodies to turn the nozzle into a nozzle sprinkler in a separate blog post.

Sensors give you the ability to dynamically adjust irrigation to local conditions. On the one hand, this allows irrigation to be perfectly tailored to the requirements of the lawn and plants, and on the other hand, it helps to save water and you don’t have to worry about manually adjusting the irrigation to the seasons and weather conditions. This blog post gives you an overview of the different types of sensors, how they work and which products are available on the market.

There are two types of rain sensors:

• Rain sensors that use a lens to optically register when it rains and as a result prevent the planned irrigation from starting or stop an irrigation run that has already started
• Rain sensors that measure the amount of rain that has fallen and, if this exceeds a certain value, ensure that the irrigation is suspended. This is done by the sensor sending an off pulse to the irrigation computer as soon as the limit value is exceeded. With most sensors, the limit value can be set individually, with the Rain Bird RSD, for example, between 0.12 and 0.75 inches of rain. The setting you make depends on the planned frequency of watering and the water requirements of the area to be watered. With modern sensors, the amount of rain is no longer measured directly by measuring the amount of rain collected, but with the help of a cork-like material built into the sensor, which collects the liquid and expands the wetter it gets. When the rain stops, it dries up again and gradually shrinks back to its original size. Only when it falls below a specified value is the suspension of the irrigation ended again by the sensor no longer sending the off impulse to the irrigation computer. The programmed irrigation program is then continued. It is important to mount the sensor on an open, unprotected area so that the rainfall is the same as the rainfall that arrives on the area to be irrigated. The solar radiation should also correspond to that of the irrigated area: If the irrigated area is in the sun most of the time, for example, then the sensor should also be installed in a similar place so that the evaporation also corresponds as closely as possible to the actual conditions.

The first type described, which works with optical means, is now outdated and is hardly offered anymore. In this category I would only know the electronic rain sensor from Gardena. The second type includes the Rain Bird RSD, the Hunter Mini-Clik and the Hunter Rain-Clik. The Rain-Clik differs from the other two rain sensors in the built-in “Quick Response” function. This causes the sensor to stop irrigation almost immediately in the event of rain. Depending on the weather, irrigation is interrupted in such a case for 3 minutes to 4 hours. The Rain Bird Sensor and the Hunter Mini-Clik, on the other hand, only do this at the moment when the set limit has been exceeded. Everyone has to decide for themselves whether this is an advantage or not. The main argument for the Hunter Rain-Clik’s Quick Response function is that the neighbors don’t look funny when you water when it’s raining. On the other hand, even a short drizzle causes irrigation to stop. In the case of weekly watering, this can mean that the lawn remains practically without water for a week. The lawn may then not receive the necessary minimum amount of water and be damaged. The Rain Bird RSD and Hunter Mini-Clik, on the other hand, only stop when the limit value is reached, so it can also happen that there is parallel irrigation during a heavy downpour. The sensors only interrupt when the limit value is reached.

Can the rain sensors be used across manufacturers?

Most rain sensors work on the same “normally closed” principle. As long as the sensor is dry and the threshold value has not been reached, the sensor circuit is closed. Only when the threshold value is exceeded, i.e. the rain sensor is triggered, is the circuit opened and the connection to the solenoid valves interrupted -> the signal for sprinkling is not received. Only when the wetness in the sensor is so low that the circuit is closed again is the connection to the solenoid valves restored and irrigation can be carried out again. The three previously presented Rain Bird RSD, Hunter Mini-Clik and Hunter Rain-Clik, for example, work according to this principle and can therefore also be used with irrigation computers from the other brand. Hunter also states that its Rain-Clik sensor can be used with most irrigation computers.

Of course, this compatibility does not apply to manufacturers whose rain sensors work according to a completely different principle, such as Gardena.

Wireless rain sensors

The sensors listed above are sensors that are connected to the water computer via a cable connection. Alternatively, models that work wirelessly are also available. The impulse from the rain sensor is sent wirelessly to an additional wireless receiving station that is installed near the water computer and then forwards the signal to the computer via a cable connection.

Rain sensors at Amazon

Following are Amazon links to some of the wired and wireless rain sensors presented.

Wired rain sensors

Wireless rain sensors

Soil moisture sensors go one step further than rain sensors. While rain sensors only measure how much moisture comes into the soil through rain, soil sensors work directly with the plants and measure how much moisture is actually available to them at the current time. For this purpose, the amount of moisture in the soil is usually measured every 10 minutes in the root area of ​​the plants. For lawns, the area of ​​concern is approximately 6 inches below the surface of the ground.

The basic functionality of the soil moisture sensor is very similar to that of the rain sensor: As soon as a specific event occurs, a signal is sent to the irrigation computer and irrigation is suspended. In the case of the soil moisture sensor, the event is exceeding a certain minimum moisture level specified by the user.

How do you find the right humidity level?

Exact instructions can be found in the product descriptions of the individual manufacturers. In principle, it works like this: you water the lawn or other plantings with the ideal amount of water and then – after a few hours – measure the moisture level in the root area. So, for example, in the evening you water your lawn with the required amount of water, 0.6 gallons per square foot, and then measure the moisture level in the root zone at a depth of 6 inches the next day in the morning. This measurement can be performed with the corresponding function of the soil moisture sensor.

You now know the moisture level with which the lawn is ideally supplied with water. If this level prevails, there would be no point in irrigating. Starting from this level, you now determine at which value irrigation should be carried out again, e.g. if the humidity is only 80% of this level.

Tight watering rhythm

Accordingly, the sensor would stop watering at any value above that. In order for this to work sensibly, the watering rhythm should be defined as closely as possible, i.e. so that watering is programmed in at daily intervals or even several times a day. Of course, this does not take place every day because the high humidity level prevents it. But this guarantees that if the moisture level falls below the required level, the waiting time until the next watering is as short as possible.

Correct positioning

The sensor shall be placed in a location of an irrigation sector that is typical of the sectors to be irrigated. In this way, the humidity level prevailing there is correctly reflected. If control via the soil moisture sensor does not make sense for all sectors, sectors can be explicitly excluded from control via the sensor. When positioning the sensor, care should also be taken not to place it in an area where water collects, e.g. next to sidewalks. And also not in places that are more shady than is the case on average.

Manufacturer-dependent differences

There are important differences in how the sensors work, depending on the manufacturer:

Rainbird

The Rain Bird Sensor SMRT-Y reports at the beginning of a watering program whether the moisture level requires watering. If this is the case, then the watering program will be completed in any case, even if the moisture level during watering exceeds the threshold. It is therefore irrelevant in which of the sectors the soil moisture sensor is placed, since an increase in the moisture level due to the watering that has just been carried out does not lead to a premature stop of the watering. In any case, all sectors are always watered.

According to Rain Bird, it can also be used together with the Rain Bird RSD rain sensor. The two sensors would then have an additional effect, i.e. only if both the rain sensor does not report that the rain limit value has been exceeded and the soil moisture sensor does not report that the minimum moisture level has been exceeded, watering takes place.

Hunter

The Hunter Soil-Clik works differently. Here, an increase in the moisture level during the already started irrigation is taken into account. If, for example, it starts to pour during irrigation and the soil is soaked much earlier, then the irrigation will be stopped early if the minimum moisture level is exceeded. The disadvantage of this variant is that you are limited in the placement of the sensor. This must be installed in the sector that is the last to be run through by the watering program. Otherwise, the watering of one sector would stop the watering of the following sectors due to the resulting increase in moisture. A special feature of the Hunter Soil-Clik is that the measuring probe is separated from the display. With the other manufacturers, this is always a unit. This has the advantage that the probe can be positioned more flexibly, as it is completely hidden underground and there is no display on the surface. The display can be installed in a completely different place and is connected to the measuring probe with a cable. It is therefore not in the way when mowing.

Hunter also recommends the Hunter Soil-Clik in combination with the Hunter Solar Sync (see description below). The Solar Sync would then ensure that watering does not take place when it is raining or freezing and that the irrigation runtimes are adapted to the current weather situation. In addition to the Solar Sync, the Soil Click prevents watering when the soil moisture is still sufficient.

Gardena

With the Gardena smart sensor, exceeding the minimum moisture level leads to a stop, as with the Hunter model, even if watering has already started.

In addition to soil moisture, the smart sensor also measures the temperature and works without a cable connection. In order to be able to use it, the purchase of two further Gardena smart products is necessary: ​​A Gardena gateway, which is connected to the W-LAN or LAN and communicates with all Gardena Smart products. And a Gardena smart Irrigation Control or Gardena smart Water Control sprinkler computer, which receives the impulses from the smart sensor and incorporates them into the sprinkling. Exceeding the set minimum moisture level stops watering, as with the sensors described above. The measured temperature has no influence on the irrigation and is only displayed to the user in the app for information purposes.

Toro

Toro also offers a wireless soil moisture sensor with the Toro Precision Soil Sensor. Practical: the compact sensor probe is pressed flat into the ground so that it can simply be driven over when mowing the lawn. Toro enables the secure irrigation of all sectors by the sensor observing a 4-hour waiting period after the start of irrigation, during which – even if the limit value should be exceeded – a stop is not reported under any circumstances.

Soil Moisture Sensors on Amazon

Following are Amazon links to the presented soil moisture sensors.

These are also called water flow meters and are used to measure how much water is going through the irrigation pipeline. On the one hand, this serves to make irrigation more economical and environmentally friendly by analyzing the consumption of a single irrigation run or, for example, an entire irrigation season and consequently optimizing water consumption. On the other hand, water flow sensors are used for safety reasons to monitor the correct functioning of the irrigation system and to rule out possible damage caused by valves that do not close or open.

In conjunction with an irrigation computer, the sensor detects when a noticeably large amount or noticeably little amount of water is being used during an irrigation cycle, or when water is being used even though no irrigation is running at all, and the operator of the irrigation system is then automatically notified or an additional master valve is closed .

There are three different types of water flow sensors on the market:

Stand-alone devices

These are sensors to be used independently of an irrigation computer, which show the water consumption directly on the sensor with a display or a built-in meter. Such a sensor is simply installed at the point in the pipeline where measurements are to be taken. Depending on the product, the functionality is limited to measuring only, or additional functions such as determining seasonal consumption, daily consumption or consumption per irrigation run are also included. This group of devices includes, for example, the Gardena AquaCount, the Rainpoint water meter or the Orbit 56854 water flow meter.

Fixed devices installed in an irrigation computer or devices that only fit a specific computer

The Orbit B-hyve smart hose faucet timer, for example, is sold with an already integrated water flow sensor. For a surcharge of approx. 50 USD, the LinkTap G2 can be expanded with the appropriate water flow sensor. Both computers have the appropriate software with which the measurement results of the sensor can be processed or functions can be made dependent on them.

Both computers are watering computers with a magnetic valve through which the water flows built into the computer. The range of water flow meters for this type of irrigation computer is very small, and I am not aware of any sensors that can be used across manufacturers in this area.

Manufacturer-independent usable water flow sensors

Such sensors are currently only offered for irrigation computers for external solenoid valve control. In order to use them, the computer must either have a dedicated water flow sensor input or the ability to configure the sensor input as a water flow meter input, such as is the case with the Hunter Hydrawise system.

Similar to a rain sensor or soil moisture sensor, the water flow meter does not send any specific values, but only electrical impulses. Each of these impulses stands for a certain number of gallons of water that has flowed through, and based on the number of reported impulses, the irrigation computer extrapolates the amount of water that has flowed through. For example, if an impulse means 1 gallon and the sensor reported 10 impulses, then the water computer calculates a consumption of 10 gallons.

This type of sensor is also used in the professional sector and starts at around 150 USD. This type includes the Hunter HC flow sensor and the Rain Bird MJ flow sensor.

This means sensors that cover not just one, but several areas. These include the Rain Bird WR2, previously presented under the rain sensors, and the Hunter WRF-Clik. In addition to the rain sensor, both also contain a frost sensor. They not only suspend irrigation when a certain amount of rain is exceeded, but also when the ground freezes. The same applies to the Toro Precision Soil, which combines a soil moisture sensor with a frost sensor.

The Hunter Solar Sync goes even further: It includes a rain sensor and a frost sensor, so the irrigation is suspended in frost and when a certain threshold of rain is reached. In addition, it measures the temperature and the intensity of the solar radiation and uses this to calculate the water evaporation (evapotranspiration). Based on this, the sensor reports an adjustment value to the irrigation computer once a day, based on which the irrigation computer dynamically adjusts the irrigation runs by changing the seasonal adjustment value. This means that the watering runs are shorter when it is less warm than at the hottest time of the year (= reference value). If, for example, 3 watering runs of 30 minutes each are stored, they may only be run for 25 minutes each. The sprinkling computer thus reacts automatically to the climatic conditions prevailing at different times of the year.

As an ideal scenario, Hunter recommends using the sensor together with its Hunter Soil-Clik soil moisture sensor, which, in addition to the above, would also mean that watering would be omitted completely if the soil moisture was sufficiently high.

A few other types of sensors are available on the market, which are usually not that interesting for private users in most cases:

• Wind sensors
• Frost sensors
• Small weather stations

Wind sensors measure the wind speed and stop sprinkling if the wind speed is too high. This avoids watering areas that should not be watered due to the throwing distances, which are greatly changed by the wind.

Frost sensors have already been presented above in combination sensors. They are also sold individually and prevent watering when there is a risk of frost.

In agriculture and other professional areas, small weather stations are sometimes used in order to be able to precisely adjust the irrigation. The costs here start at a few thousand USD.

Cover image: Hunter

In this blog post you will find an overview of the solenoid valves available on the irrigation market and their performance data. You will also find out which functionalities are important for you as a private user and which advantages they bring.
Further background information on control with solenoid valves can be found in the “Control” section.

The first very important point that distinguishes the solenoid valves available on the market is the energy supply:

Electric or battery operated

A very important point when buying the solenoid valves is whether or not there is a power connection available to control the valves. In the first case, the irrigation computer is connected to the power supply and from there 24 volt AC lines are routed to the valves. In the second case, a battery-powered watering computer is used. The valves are connected to this via 9 volt DC lines.

This requires different solenoid valves! The solenoid valves offered on the market are usually 24 volt AC valves. If you want to use this in combination with a battery-powered irrigation computer, you have to replace the 24 volt AC solenoid attached to the valve with a suitable 9 volt DC latching solenoid. Such replacement solenoids are offered by all major solenoid valve manufacturers, I present them at the end of the article. The use of 9 volt DC latching solenoid valves is therefore somewhat more expensive, since you have to buy the appropriate 9 volt replacement solenoid in addition to the actual solenoid valve.

The valves usually work in the same way across brands, so there shouldn’t usually be a problem mixing valves from different brands or swapping one brand valve for another brand valve, as long as you stay in the 9V DC or 24V AC range. Only the 9 volt replacement solenoids do not always fit across providers!

With flow regulation or not

By default, the flow on the valve cannot be adjusted. But almost all brands also offer models where this is possible. This can be useful to adjust the amount of water flowing through specifically for this one sector, e.g. to reduce the range of the sprinkler for the entire sector.

Tip: Even if you can’t think of a necessary application at the moment, it’s best to buy the valves with flow control anyway! They hardly cost more and just in case it doesn’t hurt to have this additional option.

Below is a selection of Flow Control Solenoid Valves with performance data:

Jar Top – One touch maintenance or not?

You may have noticed that some of the solenoid valves listed above have the suffix “Jar Top” added to them. This describes the property of the valve being able to be opened for maintenance with a turn of the hand. Like opening a pickle jar a quarter turn.

Tip: This is particularly important in the professional field, where every second of delay causes personnel costs and thus costs money. In the private sector, where you rarely deal with the valves, this is not really necessary. The Jar Top valves cost about the same, so whether you want to use this version is a matter of taste.

Low flow capable or not?

To function correctly, the valves require a certain minimum amount of water to flow through them. This quantity is included in the table as the minimum flow rate. Valves that require a very small amount of water, such as only 13 gallons per hour, are referred to as “low flow capable”. These can then also be used without any problems for small micro-irrigation sectors with very little water consumption. The valves listed here all have very low minimum flow rates.

Pressure range and maximum flow?

In any case, the use of the solenoid valves must remain within the maximum water pressure and water flow limits specified by the manufacturer. Although that will not be an issue with a normal private system. Even the smallest of the valves featured here have a rating of 1,800 gallons/hour and 145 psi of water pressure. These are far higher values than occur with conventional irrigation.

In-line valve, angle valve, in-line and angle valve?

This is about the design of the valves. With the in-line valve, the inlet is on the right and the outlet is on the left. With the angle valve, the inlet is at the bottom and the outlet is on the right. This has advantages in terms of pressure loss, which is why this type of valve is often used in the professional sector. If you work with not so high pressure, the difference is rather small and therefore usually negligible for private users. The argument that counts here is that the valves can be easily installed in the valve box. The third type is the in-line and angle valve. This offers both options, it can be used as an in-line valve or as an angle valve. It has an inlet on the left and below and an outlet on the right. If you connect something to the inlet at the bottom, the inlet on the left closes and vice versa.

Different threads

The last point to watch out for is the different threads: Firstly, the valves are offered with different connection thread sizes and secondly as either male or female threads. The same solenoid valve model is often available with a wide variety of thread designs.

Tip: It is best to think about how you want to mount the valve before you buy it. In most cases the standard version will fit. If not, then you can make your life easier and grab the right thread design right away to save yourself the use of unnecessary spacers during assembly.

Below is an overview of solenoid valve models without flow regulation:

Convert 24 volt solenoid valve to 9 volt solenoid valve

To convert a 24 volt solenoid valve into a 9 volt solenoid valve that can be used with a battery powered water timer, there are offered 9 volt replacement solenoids on the market that can be used to replace the 24 volt solenoids attached to the solenoid valve. The sales offers show which solenoid valves the replacement solenoid is compatible with.

In order to choose the right sprinkler, knowledge of the properties and performance data of the sprinklers available on the market is necessary. This can be found mostly on the manufacturer’s websites or sometimes hidden in operating instructions or planning documents produced by manufacturers. I have compiled this information and put together an overview of the most important key data such as throw distance, flow rate and precipitation rate of the sprinklers commonly used in private use on this page. Important attributes such as MPR capability, the option of pressure regulation, the number of model versions, available nozzle sets and much more are also listed for each sprinkler.

Basic information on the four most important manufacturers Gardena/Orbit, Hunter, Rain Bird and Toro can be found in a separate article:

Blog post comparison of the 4 manufacturers Gardena, Hunter, Rain Bird and Toro

If you would like to know which sprinkler model from which manufacturer I personally recommend buying, visit the buying section of this website! There you will also find purchase recommendations for pipeline, connectors, control units, solenoid valves, etc.

A brief explanation of the technical terms listed here, such as flow rate, precipitation, MPR capability, pressure regulation, etc. can be found at the very end of this page following the performance data listed.

The geared sprinklers available on the market, also known as rotary sprinklers, are presented on this page. The smaller spray sprinklers (or just sprayers), which have a completely different functionality and other areas of application, are covered in the separate blog post “Overview of the spray sprinklers available on the market” . The Hunter MP rotators and Rain Bird R-VAN, which as rotating nozzle sprinklers actually form their own category and which can be used both in place of a geared sprinkler and in place of a sprayer, are included in both places for the sake of clarity.
The comparison is broken down by manufacturer. It starts with the Hunter products, followed by Rain Bird, Toro and Orbit. Each manufacturer is preceded by a short introductory text in which the manufacturer’s product range is summarized. This is followed by the essential performance data and a tabular overview of throw, flow rate, etc. at specific pressures or for specific models. I have also added my personal rating and a comment to each sprinkler and at the very end there are web links to purchase options for the corresponding sprinkler.

Hunter basically has 6 different geared sprinklers that are suitable for private users:

About the Hunter product range

There are also larger Hunter I-sprinklers, but these are aimed at commercial users with large areas to be irrigated and are not dealt with here. The Hunter SRM is also left out, which can’t do anything that the other products presented couldn’t do either.

The sprinkler models presented still have subgroups. These are distinguished by an additional number after the sprinkler designation (e.g. PGP Ultra-04) and represent different heights of riser, with the number indicating the height of the riser in inches. Thus, the PGP Ultra-04 designates a sprinkler with a 4-inch riser, the PGP Ultra-12 the variant with a 12-inch riser and if there is a -00 after the sprinkler name, it means that the sprinkler has no riser at all, i.e. it is a non-retractable standpipe sprinkler.

The Hunter MP Rotator is actually a completely separate category – located between a geared sprinkler and a spray sprinkler. This came into the Hunter range as part of the takeover of the Walla Walla Sprinkler Company in 2007 and has a completely different technology than the other Hunter sprinklers. The Walla Walla engineers were way ahead of their time and have already taken many things into account whose importance and usefulness are widely accepted today. They also differ from geared sprinklers in that the body and the actual sprinkler, including the nozzle, are separate. Sprinklers and nozzles can be combined with a suitable body according to the user’s choice. Since there is nothing else like it in this category and since they can be used like a rotor, the MP rotators are included in the rotors.

Now a brief definition of what fundamentally distinguishes the sprinkler types presented:

Classification of Hunter sprinklers

• The Hunter PGJ is the entry-level model. A stripped down sprinkler, reduced to the basic functions, at a very reasonable price
• The Hunter PGP is the battleship Hunter introduced to revolutionize the sprinkler market in 1981 and is still the world’s most sold sprinkler. A solid, well-functioning sprinkler, which is now getting a bit old and does not contain things that are state of the art today.
• The Hunter PGP Ultra is the successor to the Hunter PGP, which incorporates the findings of almost 30 years of market observation. It’s a bit more robust than the PGP, and Hunter offers a five-year warranty instead of the two-year warranty. In addition, more nozzle sets can be used and, above all, MPR nozzles can be used in this sprinkler, which makes it possible to adjust the precipitation rate. It also has (in the “PRB” version) a pressure regulating body that ensures that the pressure in the sprinkler is regulated down to a maximum of 45 psi. There are also practical things such as remembering and returning to the set sprinkler circle if the sprinkler is rotated manually.
• The Hunter I-20 was introduced a few years before the PGP Ultra and does essentially the same thing as the PGP Ultra. The only difference that I can see is that it is a little more robust (according to Hunter sports field suitability) and that the I-20 is also available in a stainless steel version.
• As previously written, the Hunter MP Rotator is a model with a completely different technical philosophy. Like a spray sprinkler, it releases the water in all directions at the same time, but not in one gush of water, but divided into many fine water jets by rotating the sprinkler head. This happens at a low flow rate, so the sprinkler releases water relatively slowly. This has the advantage that a relatively low water pressure is required and that more sprinklers can be operated in one sector. The MP-Rotator has an integrated MPR principle. This automatically ensures an even precipitation rate for all nozzles and models. In conjunction with a pressure-regulating body, the pressure is automatically reduced to 40 psi or 30 psi. You could describe the MP-Rotator as something like the carefree package among sprinklers that automatically prevents many possible sources of error that lurk in the implementation of irrigation. It is very suitable for small and medium-sized gardens and is also my top purchase tip for them.

Rating

Comment: The Hunter PGJ is Hunter’s entry-level model, but it’s already a solid sprinkler. The precipitation rates can be adjusted manually (MPR) using the 8 nozzles that are included as standard. There is no option to regulate the pressure, and no other nozzles can be used apart from the nozzle set that is included. I rate the PGJ 3 out of 5. There are better sprinklers out there from Hunter, but the Hunter PGJ offers pretty decent performance for the price.

Hunter PGJ on Amazon:

Rating

Comment: The Hunter PGP is a very solid sprinkler, it was the best selling sprinkler in the world for many years with good reason. Compared to the Hunter PGJ, it also has the advantage of a larger throw distance and that you can choose from a total of 3 nozzle sets. In principle, you can’t go wrong with the purchase of this sprinkler even today. Except that there are now even better ones that also handle MPR, pressure regulation and a few other small things. Rating of 3.5 out of 5 points. A bargain for this price! If you want it very cheap but still good, an alternative worth considering.

Performance Data Hunter PGP

Below you will find tables with radius, flow and precipitation rate for all available nozzle sets. For better clarity, this data is only displayed after clicking on the corresponding nozzle set variant:

Hunter PGP on Amazon:

Rating

Comment: The Hunter PGP Ultra is the further development of the PGP, in which the knowledge from several decades has flowed. The most important advantage is the possibility to use MPR nozzles, i.e. to coordinate the precipitation rate. The automatic arc return feature, which ensures that the sprinkler waters the correct sector if someone accidentally turns it, is also very pleasant in practice. I rate it 4 out of 5. Since it costs little more than the Hunter PGP Adj, you don’t need to think twice and can immediately go for the better model. A very good sprinkler at a top price!

The PGP Ultra is now also available as “Ultra PRB” in a version with a pressure-regulated body. The water pressure at the sprinkler is automatically reduced to 45 psi. Since the lack of pressure regulation was the last remaining shortcoming, I am increasing the rating for the PRB version to 4.5 out of 5 points. At the current time, a small negative aftertaste is the very strong price difference between the normal and the PRB version. Hopefully the price will fall as well.

Performance Data Hunter PGP Ultra

Below you will find tables with radius, flow and precipitation rate for all available nozzle sets. For better clarity, this data is only displayed after clicking on the corresponding nozzle set variant:

Hunter PGP Ultra on Amazon:

Rating

Comment: The Hunter I-20 is practically identical to the PGP Ultra in terms of performance data, it also uses the same nozzle sets. It is made a little more robust (according to Hunter sports field suitability) and is offered in a stylish stainless steel version. Like the PGP Ultra, I rate it 4 out of 5. Here, too, a “PRB” version with pressure regulation is now available. For this I increase the rating to 4.5 out of 5 points.

From my point of view, the additional robustness is not necessary for normal private use, the PGP Ultra is also very robust. Therefore I would – because the I-20 is a bit more expensive – resort to the PGP Ultra, which can do exactly the same thing. Unless you absolutely want a chic stainless steel version, which is only available on the I-20.

Performance Data Hunter I-20

Below you will find tables with radius, flow and precipitation rate for all available nozzle sets. The nozzle sets of the I-20 are identical to those of the PGP Ultra. For the sake of clarity, the data is only displayed after clicking on the corresponding nozzle set variant:

Hunter I-20 on Amazon:

MP1000, MP2000, MP3000, MP3500

Rating

Comment: The Hunter MP Rotator is my top pick! I give it a maximum of 5 points. It automatically provides an even precipitation rate (MPR) using built-in functionality, and when used with Pro-Spray-PRS bodies, it also has built-in pressure reduction to 40 or 30 psi. With its low water pressure and water volume requirements, it is also a good alternative when resources are scarce and it allows more sprinklers to be operated in one sector. The price is also good, even if you go for the more expensive pressure-reducing case, which I definitely recommend. The very easy exchangeability of sprinklers is also practical: If, for example, the range of the MP2000 turns out to be too short, an MP3000 is simply screwed into the housing and it fits again. You don’t have to pay attention to the precipitation rate, as this always remains the same across models in the MP1000, MP2000, MP3000 and MP3500 universe. Even if you change sector or throw distance! You could therefore describe this sprinkler as something like the carefree package among sprinklers, which ensures that the user automatically gets many things right.

Performance Data Hunter MP-Rotator

Below you will find tables with radius, flow and precipitation rate for all available models and model variants. For the sake of clarity, the data is only displayed after clicking on the corresponding  variant:

Hunter MP-Rotator on Amazon:

This is a so-called strip sprinkler, which was specially developed for sprinkling long, narrow areas. To irrigate a strip, 3 sprinklers “left corner”, “right corner” and “middle” must be installed.

MPLCS515 (Left Strip), MPRCS515 (Right Strip), MPSS530 (Side Strip)

Rating

Comment: Irrigating long, narrow strips is one of the most difficult tasks in irrigation technology. Sprinklers usually irrigate in a circle, but here a spray pattern that is as rectangular as possible is required. From my point of view, this is probably never possible in a 100% form. Even the MP-Rotator side stripe sprinkler does not succeed perfectly, but in an appealing way that you can work with. In view of the other advantages of the MP-Rotator model series also contained here (see evaluation of the MP-Rotator sprinkler above), I rate it with 4.5 out of 5 points.

Below is a tabular listing of radius, flow and precipitation rate for the three strip models:

Hunter MP-Rotator MP Strip on Amazon:

Below is an overview of the Rain Bird sprinklers that are of interest to private users:

About the Rain Bird product range

Like Hunter, Rain Bird has a wide range of rotors. Part of it is explicitly aimed at commercial users such as golf courses and large parks and not only makes no sense for private users, but would also not be usable at all due to the sometimes very high water pressure and water volume requirements. Therefore, the sprinklers of the Eagle series and the 500 and 700 series are not presented here. The Rain Bird 8005 is also left out, as its use makes no sense for 99% of readers.

It is obvious that almost every Hunter sprinkler has a counterpart at Rain Bird and vice versa. The Rain Bird 3500 is comparable to the Hunter PGJ, the Rain Bird 5000 is the counterpart to the Hunter PGP Ultra and the Rain Bird R-VAN is clearly modeled after the Hunter MP rotator. You can see that there is fierce competition between these companies and good ideas from one are immediately incorporated into the product range of the other.

The Rain Bird Maxi-Paw has a unique selling point in the Rain Bird range. It is not a geared but an impulse sprinkler. So the classic sprinkler that you know from fields or large meadows and which makes the noises typical of impulse sprinklers when sprinkling by breaking the jet. Impulse sprinklers are indeed also offered by other manufacturers, but not – as by Rain Bird – in a retractable version.

Rain Bird R-VAN is the counterpart to the Hunter MP-Rotator – i.e. a hybrid of sprinkler and sprayer – and (almost) equal to it.

Now a brief definition of what fundamentally distinguishes the Rain Bird sprinkler types:

Classification of Rain Bird sprinklers

• The Rain Bird 3500 is Rain Bird’s entry-level model and a direct counterpart to the Hunter PGJ. A properly functioning sprinkler reduced to the basic functions at a very attractive price.
• The Rain Bird 5000 is my favorite Rain Bird sprinkler. The counterpart to the Hunter PGP Ultra and absolutely on a par with this very good sprinkler. It can be used with MPR nozzles and is available with a pressure-regulating housing. Compared to the PGP Ultra, the pressure-regulated version has a clear price advantage at the time of my research.
• The Rain Bird Maxi-Paw is the only retractable impulse sprinkler available on the market and an interesting alternative for fans of this sprinkler shape and if the slightly higher noise level is not a problem.
• The Rain Bird Falcon 6504 is already very close to the limit of a sprinkler for the purely commercial sector. Very robust and the only sprinkler with a so-called “high-speed mode” (particularly fast rotation). However, important functions such as MPR and pressure regulation are missing.
• Rain Bird R-VAN is the counterpart to the Hunter MP Rotator. So actually not a sprinkler, but a sprayer with a rotating head. The Rain Bird version of the multi-jet rotary sprinkler is also very successful.

Rating

Comment: The Rain Bird 3500 is the Rain Bird entry-level sprinkler and direct opponent of the Hunter PGJ. Just like this one, it’s a very solid sprinkler. With the 6 nozzles included, only a very rough adjustment of precipitation rates is possible. There is no way to regulate the pressure and no other nozzle sets that can be used optionally. I rate the Rain Bird 3500 3 out of 5. If the demands are not too high, a good alternative, especially for the low price!

Rain Bird 3500 on Amazon:

Rating

Comment: The Rain Bird 5000 is an excellent sprinkler, very reliable and has all the important features. He is the direct opponent of the Hunter PGP Ultra and on the same level. MPR nozzles can also be used with the Rain Bird 5000 and thus achieve a uniform precipitation rate. And it can also be purchased with a 45 psi case pressure-regulated body (Rain Bird calls this option “PRS”). So here too there are 4 points for the standard version and 4.5 points for the more expensive version with PRS.

It is worth mentioning that the price of the Rain Bird 5000 with PRS is significantly lower in my research compared to the Hunter PGP Ultra PRB counterpart. And with the PRS versions, Rain Bird gives you the stainless steel version for practically the same price. Not that you would necessarily need it, but it definitely looks chic.

Performance Data Rain Bird 5000

Below you will find tables with radius, flow and precipitation rate for all available nozzle sets. For better clarity, this data is only displayed after clicking on the corresponding nozzle set variant: