Buying Guide: These factors allow you to compare and rate irrigation computers

Which irrigation computer is right for you depends on your needs. First of all, it is very important to know how to water your garden.

For this purpose, it makes sense to create an irrigation plan for his garden or balcony. Purchasing an irrigation computer only makes sense if you know how many irrigation lines need to be installed, each with how many devices.

Of course, the computer alone can not irrigate your garden, and if you do not make a plan, then you do not know exactly what accessories you need later for your system.

When planning your own irrigation system, pay special attention to the number of sprinklers and their technical data. If you know how many water distributors the irrigation computer should control, you can buy the appropriate device model.

Over time, you may need to expand your irrigation system. That’s why you should make sure that the desired model is expandable or holds connections for extras.

After the plan is before the purchase. The following criteria determine the price of your watering computer at the end:

  • The energy supply
  • Connection for sensors
  • Watering cycles
  • Watering time
  • Watering frequency
  • Automatic on / off
  • Battery charging indication
  • Delivery
  • Display

The most important criteria I have listed above, now we will go into each point, so you can get an overview of the device which is best for you.

The energy supply

Since water and electricity are not a good combination, most manufacturers offer batteries to their devices, which are often not included in the delivery.

There are basically 2 types of batteries that are used more often here. Either 1 time the 9 volts or 2 times the 1.5-volt alkaline battery. The batteries are usually sufficient for a season and sometimes beyond.

Some devices can now be purchased with solar storage, but are best suited when they run in combination with a battery. The batteries are charged via the solar cells and can thus maintain the operation of the device even on cloudy days.

It should be noted that the device is oriented so that it gets as much sun as possible. Furthermore, it is, of course, to make sure that the battery is protected from moisture and moisture. Otherwise, damage may occur.

Connection for sensors

Soil moisture and rain sensors are the two most important sensors of every garden lover. Therefore, when buying the watering computer, make sure the model has sensor connections.

Although these sensors are not essential to the operation of the watering computer, they can help to water accurately and waste unnecessary resources.

The soil moisture sensor is positioned between the plants and measures the degree of soil moisture at regular intervals. Irrigation will only be activated if the measured value of soil moisture is less than the gardener’s set target value.

The rain sensor, on the other hand, can detect rainfall based on humidity. If it rains during the irrigation period, irrigation is stopped.

Watering cycles

How often can such an irrigation cycle be carried out? Depending on the selected model, the values vary greatly. For the low-priced products, a watering cycle of no more than once a day. Most devices allow irrigation 2-3 times a day.

The higher quality models support up to 6 different passes a day to water your green area. Since it is advisable to water his garden in the morning and in the evening, usually enough is a device with which you can water 2-3 times a day.

It should be possible in between to manually operate the watering computer in case you want to sprinkle your lawn at short notice unscheduled. All devices have this option.

Watering time

How long does irrigation take? As well as in the irrigation process, the values here vary depending on the model. The maximum adjustable values for duration are 1 hour and 10 hours for the higher quality models.

For a normal small garden, a duration of up to a maximum of 2 hours is recommended. So you can be sure that hidden flowers and the hedge (even the hard to reach interior) will water well.

Watering frequency

The interval also plays a major role in irrigation. How often should your green be watered? By default, most irrigation computers are set to 24 hours. That is, the water computer should be able to perform the set irrigation cycles every 24 hours.

Some models allow shorter intervals, for example, 12 hours. Others only allow higher intervals. So the garden will water only every 2nd, 3rd, 4th, 5th, 6th, or only once a week, which under certain circumstances and depending on the plant species may not be enough.

Individual models have unique selling points such as selectable days of the week, a large number of selectable programs, a multilingual user interface, and similar benefits that everyone has to choose for themselves.

Automatic on / off

Once set, the irrigation computer takes control of the faucet and control over the plant. Here’s the difference between a common watering timer and an irrigation computer.

The irrigation computer can independently start and stop the irrigation process. In cooperation with sensors, the irrigation computer is even more efficient. With the clock, however, you still have to initiate the startup process yourself. It is therefore advisable to buy an irrigation computer that allows this option.

Battery charging indication

There is no battery included with the purchase of the watering computer. That means you have to buy this yourself. They do not cost much and are usually available in retail stores. The batteries usually last beyond a garden season.

Still, it can be helpful to see the status of the battery so you know when to change it, or why your irrigation computer is not working as reliably as it should.


Most modern irrigation computers come with a display where you can easily check and configure all values and inputs. The larger the display, the more comfortable the use.

For some models, it can even be easily removed. In contrast, particularly favorable variants can only have a rotary switch which limits the functionality to a minimum.

Thread and pressure

An important point is the connection of the watering computer: is a faucet or a water valve supported? Or is the irrigation computer also compatible with the rain barrel?

If the irrigation system is to be operated via a tap, the necessary water pressure must be observed. Depending on the size of the system and the amount of water pumped, higher water pressure is required.

Most devices are compatible with G 3/4 threads with a diameter of 26.5mm and with G 1 thread (33.3mm). Also, the water pressure of 0.5 to 12 bar is supported.

However, there are also devices that are not built for the water pump. These are often usable without pressure because they are intended for the rain barrel. Here, the rain barrel is placed in an elevated position and the water computer or the clock makes use of gravity.


Most appliances come from home without batteries. In the packaging is the ordered model and depending on the device additionally the battery charge indicator, a mostly removable LCD display, a pre-filter, a user manual in several languages and a sensor connection. The solar-powered devices always have a lithium-ion battery.

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