With an irrigation computer, the times when lawns and plants were watered irregularly and unevenly or were completely neglected or forgotten for days are over. The device supports you in keeping your green oasis constantly healthy. You can find out from us what types of irrigation computers there are and what you should pay attention to if you want to buy such a computer.

A watering computer optimizes watering of the entire garden

Table of Contents

Show all
  1. Types of irrigation computers
  2. Other purchase criteria
  3. What brands are there?
  4. How do I maintain an irrigation computer?
  5. Which accessories are useful?
  6. frequently asked Questions

    7. Types of irrigation computers

    First it applies

    • irrigation clocks and
    • watering computer

    to distinguish. Both types can be further subdivided.

    Irrigation clocks:

    • mechanically
    • electronic

    Irrigation computer:

    • classic (without extras)
    • with humidity and/or rain sensor (connection)

    In the following we will go into all genres in more detail.

    Irrigation clocks in the test

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    Hiveseen 151 PCS Irrigation Kit, 25M Irrigation System with Adjustable Sprinkler Sprayer and Automatic Dripper for Drip Irrigation, Garden Irrigation, Greenhouse Irrigation
    20.99 EUR To the product

    Irrigation clocks are easy to program. You don't need any special programming skills to set them up for automatic watering. Anyone who has ever operated a kitchen timer in the course of their life (this should apply to most of the readers of our article) will also find it easy to use a watering timer in practice.

    Hobby gardeners like to use a watering timer to have a simple and very inexpensive technical helper for automatically watering the garden (lawn and plants). All you have to do is connect the watering timer to the tap and then set it as needed. You do not need a specialist for these tasks.

    Compared to real irrigation computers, the adjustable times are relatively inflexible. Irrigation can be timed from one minute to a maximum of two hours. This is sufficient for most users, but larger green areas require more.

    The long intervals are also a disadvantage: Depending on the model, there are always at least 24 hours to seven days between two watering processes. As you know, a week can be quite long. The same goes for fastidious plants. They need water at shorter intervals.

    tips

    Most watering timers have one to a maximum of two rotary knobs for setting the watering frequency and duration. These practical devices are often referred to as watering timers. So don't be surprised if you occasionally come across the term when comparing.

    Before we turn to the subtypes of the watering timer (i.e. mechanical and electrical), here is an overview of the general advantages and disadvantages:

    benefits
    • Easy handling
    • Simple installation
    • Individually adjustable
    • Extremely inexpensive
    disadvantage
    • Switch-on delay possible
    • inflexible times
    • long intervals

    Testing mechanical irrigation clocks

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    Gardena water timer: timer for water taps 26.5 mm (G 3/4) or 33.3 mm (G1), flexible watering duration (5-120 min), easy to connect thanks to the quick-connect system (1169-20)
    22.08 EUR To the product

    The most important properties of mechanical watering timers in bullet points:

    • also called watering timer
    • mechanically operated
    • Pressure not adjustable
    • no switch-on delay
    • no energy input
    • no automatic start of irrigation
    • automatic stop of watering
    • maximum watering time of two hours
    • Watering interval of at least 24 hours
    • just a knob

    Testing electronic watering timers

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    Royal Gardineer irrigation clock: digital irrigation computer BWC-200 with 2 connections (irrigation computer)
    32.99 EUR To the product

    The most important properties of electronic watering timers in bullet points:

    • also called watering machine
    • electronically operated
    • Pressure adjustable
    • Switch-on delay of up to twelve hours
    • Powered by batteries (usually two AA batteries, each with 1.5 volts, are required)
    • automatic start of irrigation
    • automatic stop of watering
    • maximum watering time of two hours
    • Watering interval of at least one hour up to one week possible
    • two knobs

    Even if electronic watering clocks are a little more developed than mechanical watering timers, they are not yet real watering computers.

    We will take a closer look at the latter in the next few paragraphs.

    Irrigation computer in the test

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    Hunter irrigation computer, X-Core 601i 6 stations (indoor)
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    Compared to watering clocks, watering computers generally have far more functions. In addition, they are more versatile in use. Professional gardeners usually prefer such a system, but ambitious hobby gardeners also benefit from the advantages of an irrigation computer.

    The rigid times, which are a major disadvantage of watering clocks, are eliminated with watering computers. You can reduce or increase both the exact watering times and the intervals between the individual waterings as you wish and as needed. Even multiple waterings in one day are easily possible.

    Even the most experienced and attentive professional gardener sometimes forgets to water the garden when it is due. You can skilfully avoid this problem with an irrigation computer. The helpful device never forgets anything. It takes care of everything, i.e. watering the entire garden - even if you are on vacation or not at home for some other reason.

    Installing an irrigation computer is easy: you just have to connect it to the water tap and garden hose using the appropriate connections. In this sense, the computer acts as a sort of “mediator” between the two elements.

    In most cases, watering computers are operated with a battery, which is often not included in the scope of delivery. At first glance, this point appears to be a disadvantage. A closer look shows, however, that it is not so important that the battery is missing. It can be purchased online at reasonable prices. In addition, it usually lasts for at least a year.

    A watering computer is not just a watering computer. There are different subspecies or variants:

    • classic models without extras
    • Versions with humidity and/or rain sensor

    Before we explain the most important characteristics of the different types to you, we would like to briefly summarize the basic advantages and disadvantages of irrigation computers:

    benefits
    • Flexible times
    • Individually adjustable
    • Often there is a connection for a sensor
    disadvantage
    • More expensive to buy
    • Battery usually not included

    Classic watering computers without extras in the test

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    CROSOFMI irrigation computer water timer garden timer irrigation, large 3-inch display rain delay and child lock
    30.99 EUR To the product

    The classic watering computers come without any specific extras - that means they have no connections for a moisture and/or rain sensor. Such models are comparatively cheap and are characterized by all the features of an irrigation computer (see above).

    tips

    Depending on the specific design, more or fewer setting options are available to you with a conventionally designed watering computer. Pay attention to this when buying.

    Irrigation computer with humidity and/or rain sensor in the test

    our recommendation
    Gardena water computer MultiControl duo: watering control, weekdays programmable, up to 3 waterings per day, with LC display (1874-20)
    85.99 EUR To the product

    If you want a water computer that works particularly sustainably, we recommend that you buy a model that has connections for a moisture and/or rain sensor. Ideally, the sensors mentioned are part of the scope of delivery. Otherwise, you can also buy these separately if you have existing connections.

    What is the big advantage of such weather sensors? In cooperation with the watering computer, they ensure at all times that your lawn and your plants are supplied with the optimal amount of water. You never get a drop too much (but never too little either!).

    Pleasant side effect: The perfect “dosage” of water for the garden has an extremely positive effect on your annual water bill. In short, a sensor helps to save water efficiently when watering your own green area(s).

    What is a humidity sensor?

    • This sensor is positioned between the plants in the garden.
    • It measures the prevailing soil moisture level at regular intervals.
    • The water computer only activates watering if the determined value is lower than the target value you set.

    What is a rain sensor?

    • The location of this sensor is the same as that of the humidity sensor.
    • It determines precipitation based on humidity.
    • If it rains, the water computer stops watering.

    Note: It should be noted at this point that you do not necessarily need a moisture and/or rain sensor to operate an irrigation computer. However, the sensors support the precise watering of the garden. This also prevents unnecessary waste of valuable resources.

    tips

    Always remember that the supposedly most natural good on earth - water - is becoming increasingly scarce, and deal with it accordingly. For garden owners, an irrigation computer with weather sensors can be of great help in this mission.

    But: A sensor does not always make sense, as this practical example shows: Would you like to collect rainwater in a controlled manner? Then you should buy an irrigation computer without a rain sensor.

    Other purchase criteria

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    When buying an irrigation computer you have to consider a few criteria:

    • type of system
    • thread and pressure
    • weather sensors
    • watering cycles
    • watering duration
    • watering frequency
    • automatic on/off
    • screen
    • battery level indicator
    • WiFi/Bluetooth capability
    • scope of delivery

    type of system

    First decide whether you only need a water timer or a real water computer. You can review the features of both systems above.

    thread and pressure

    How about the connections of the computer? Do they support a water valve or faucet? Is the calculator also compatible with a rain barrel?

    If you want to connect the computer to a water tap, you need to analyze the thread and pressure of the connection.

    Note: Most watering timers come with the threads

    • G 3/4 (diameter of 26.5 millimeters) and
    • G 1 (diameter of 33.3 millimeters)

    compatible. Normally, a water pressure of 0.5 to twelve bar is supported.

    weather sensors

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    275.59 EUR To the product

    The irrigation computer should have a sensor connection. It is ingenious if a weather sensor is also included.

    watering cycles

    What watering cycle does each model allow? That means: How quickly can the next watering cycle start? Only after a week, after a day or even after a few hours? What do you need for your plants?

    Note: Most units allow two to three waterings per day. And that's all it usually takes.

    watering duration

    What is the maximum watering duration that can be set? Just an hour or even ten? In principle, the following applies here again: the more options (flexibility) you have, the better it is. Two hours is enough for a small garden.

    watering frequency

    How often would you like to water your green oasis with the device? Compare the watering computers on this feature and make sure that the model of your choice is compatible with your ideas.

    Automatic on/off

    At best, the water computer is able to start and stop watering independently (ONLY possible with real water computers, NOT with water clocks).

    screen

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    The selected device should have a clear display on which you can easily check and configure all values. A model that is as large as possible is an advantage here.

    battery level indicator

    It makes things easier if the water timer has a battery charge indicator so you can make a timely replacement. This is the only way to prevent a temporarily restricted functionality of the device.

    WiFi/Bluetooth capability

    It doesn't have to be, but it's a nice feature: being able to operate the watering computer using your smartphone. This requires WiFi or Bluetooth connectivity.

    scope of delivery

    The larger the scope of delivery, the better. Ideally, you will receive your device including a user manual in several languages, a detachable display, a sensor connector and sensor, and a battery. Unfortunately, you often have to order the sensor and battery separately. Only with solar-powered watering computers is a lithium-ion battery always included.

    What brands are there?

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    Here is an overview of well-known brands that offer irrigation computers:

    • Hunter
    • Arduino
    • Royal curtainers
    • Rainbird
    • Karcher
    • Gardena

    You can find watering computers in well-stocked garden and DIY stores, both offline and online. In addition, there are several online mail order companies available as sources of supply, above all Amazon.

    How do I maintain an irrigation computer?

    Important tips for the treatment and care of a water computer:

    • Remove dust and other dirt from the device at regular intervals. For this purpose, it is best to use a slightly damp cloth and, if necessary (rarely the case…), a touch of washing-up liquid. Caution: DO NOT use aggressive detergents and do not use cleaning sponges with a very rough surface (steel wool, etc.). These utensils could attack and damage the housing.
    • Never hold the Water Computer under running water. Although it is generally waterproof (because it is designed for outdoor use), one cannot completely rule out the possibility of moisture penetrating the computer's interior in the event of high water pressure, possibly causing irreversible damage to the sensitive technology.
    • If possible, install the device in a dry and wind-protected place in the garden. Direct sunlight should also be avoided - over time it could severely damage the frame, which is usually made of plastic. Exception: An irrigation computer with a solar battery needs plenty of sunlight "by nature". A dry microfiber cloth is the ideal tool for cleaning the solar cells.
    • Always check the charge level of the battery or rechargeable battery so that you can change it early and maintain trouble-free operation over the long term. It is practical that many irrigation computers are equipped with a display for the charge status, so that you can always keep an eye on it.
    • Store the Water Computer in winter (watering no longer necessary) in a dry and well-ventilated but frost-free place. Before that, the computer needs to be thoroughly cleaned again.The weather sensors (if any) also want proper (and clean) storage.
    • Generally elementary: Read and follow the manufacturer's care instructions!
    • Any maintenance and repair work on the water computer should always be entrusted to a trained specialist. Never try to do it yourself, otherwise the manufacturer's guarantee will normally expire immediately.

    Which accessories are useful?

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    The best supplementary items for a classic watering computer are rain and moisture sensors. Maybe they are already included in the scope of delivery, that would be the best option.

    In addition, you logically need an irrigation system or the obligatory water tap and a garden hose.

    frequently asked Questions

    What is an irrigation computer?

    A watering computer is a programmable device that saves you a lot of watering work. The practical tool ensures that your garden plants are automatically watered - from the lawn to trees and shrubs to flower beds, each "department" gets the right amount of water you specify. Once set up, the watering computer supplies your greenery without any further action - consistently on the individually specified days at the desired hours.

    What is the difference between an irrigation computer and an irrigation timer?

    First of all, what they have in common: With both devices, you regulate the watering times and cycles. Compared to an irrigation timer, an irrigation computer offers a significantly larger range of functions.

    How does an irrigation computer work?

    An irrigation computer makes watering much easier

    In a nutshell: you attach the watering computer between the tap and the garden hose and program it. It then automatically ensures that the lawn is watered at the desired times.

    A little more detailed: After connecting the water computer to the tap and hose, you configure the watering cycles according to your needs. This really isn't rocket science, it's just as simple as using a pocket calculator.

    Practical: With very high-quality watering computers, you can make a large number of settings and comprehensively regulate watering.

    According to the programming, the computer's automatic system opens the valve of the tap as soon as it is the (set) time. The water flows and waters the lawn via a hose. After the watering time you have specified, the computer immediately closes the valve, interrupting the water supply.

    tips

    A watering computer with so-called soil moisture or rain sensors is particularly luxurious. Then the computer “learns” from the assistant when the soil is moist enough and it can end the watering cycle (and vice versa, when the lawn needs to be watered again).

    Who benefits from an irrigation computer?

    Anyone who owns a lawn but has little time to take care of it is doing themselves and their lawn a great favor with a water computer.

    Here is an overview of the many advantages that such a device brings:

    • Time saver (the water timer does the work for you; you don't even have to be at home and you don't have to worry about watering your lawn even on vacation)
    • optimal care (correctly programmed, the computer ensures absolutely reliable and even watering of the green area; this means that even sensitive plants grow well and do not die; in contrast to humans, the computer is not forgetful…)
    • economical use of resources (you only use as much water as you program the computer to; the computer ensures that not a drop is wasted; the environment also benefits from this)

    An irrigation computer with a moisture or rain sensor also prevents too much or unnecessary water from flowing.

    Note: Irrigation computers have long been used in larger agricultural and horticultural businesses, in public parks and gardens as well as in soccer stadiums, on golf courses and other sports-related areas. They are also increasingly used in private gardens.

    How much does an irrigation computer cost?

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    11.02 EUR To the product

    Hard to believe: Very simple watering machines are available from around ten euros. However, these simple models “only” turn the tap on and off. If you want a comprehensively programmable watering computer, you will of course have to dig a little deeper into your pocket. Here is a price overview that you can use as a guide:

    • mechanical watering timer: from approx. 10 EUR
    • electronic watering timer: from approx. 20 EUR
    • electronic watering timer for rain barrels: (53.99 €) from approx. 40 EUR
    • digital irrigation computer: from approx. 40 EUR
    • digital watering computer with two connections: from approx. 70 EUR

    Extremely functional irrigation computers cost up to 200 euros.

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