Automating your Irrigation

Tired of watering your garden by hand?  After decades of this time-consuming gardening activity, I decided to try to automate the task, and found that with modern technology it is now achievable and affordable to do so for home gardeners.  Here is what I learned.

I will focus on one brand of irrigation equipment because it is the brand I chose to purchase.  However, this is not an ad for that brand and I don't claim this brand to be superior.  The aim of this blog post is to show how today's irrigation technology can assist the home gardener.  Other brands may do an equally clever or even better job.

I wrote this blog post in January 2016.  At the end of this blog post you will find updates I added in March 2018 after having used automated irrigation for two years.  The updates are in green.

Automating my irrigation started some months ago when I had to make sure plants in my hothouse would be irrigated during a 5-day absence.  But first I had to tackle a problem with our water pressure.

Water pressure is measured in Kilo Pascals (Kpa).  We had our mains water pressure measured by a plumber.   We live in Lindisfarne, Hobart, Tasmania, Australia, and it turns out that our water pressure can be up to 1200 Kpa at times.  To put this in perspective, most manufacturers do not honour the warranty on washing machines if water pressure is over 500 Kpa.  It is good to know what your water pressure is when it comes to irrigation, because most irrigation drippers and drip-lines need a pressure of at least 50, but no more than around 300 Kpa.

So my first step was to ask our plumber to install a pressure-reducer at the point where mains water enters our property.  He installed one that limits the pressure at that point to 500 Kpa, but we can adjust it down if it needs to be lower by turning the knob (in the middle in the photo below).  Cost including installation was $A250.

If you are not worried about water pressure in relation to your household appliances you can use a plastic pressure reducer (the black item in the photo below) for each irrigation hose or pipe.  A plastic pressure reducer costs just around $10.  Before our plumber installed his device the mains pressure was so high that the plastic pressure reducer in the photo cracked!

After solving the pressure problem I focused on buying an automatic tap timer for the irrigation of my hothouse.  Suggestions by friends who bought one previously are always helpful, but the recommended brand was not available, so I started from scratch.

After comparing automatic tap timers, focusing on sturdiness, easy of programming and flexibility of watering times and durations, I took the gamble and bought a Gardena FlexControl (1883) .  The photo below shows the unit as I initially installed it.  The tap timer gets its power from a 9-volt battery.  Timer without battery cost me around $A70.

I connected a short brass male/female conversion pipe to the tap, attached to that a black plastic water filter and then the timer.  I used white plumbing tape in every connection.

This setup worked, but there was one weak point.  Walking past it, especially with a wheelbarrow, you had to be careful, because if you would push the timer, one or more of the fittings might crack or even break.

The automatic tap timer has its own basic filter.  The water coming out of our taps is not dirty on average, so I decided to go for a simpler setup, that has worked without fail since then (see photo below - no male/female converter and filter - just straight onto the tap).

This unit allows you to set one watering schedule, with great flexibility and ease.  At present (mid summer), with the tap half open, this automatic tap timer is set so it lets water flow to my hothouse at 6.00am every second day for 6 minutes.  In the hothouse tricklers hanging just above the soil level of each pot then dispers the water.

I no longer have to water pots in my hothouse by hand.  If I need to increase or decrease the irrigation time this is an easy job done on the panel of the device.

This tap timer allows you to

• water once, twice or three times per day with 8 hour intervals
• for a duration of between 1 minute and 9 hours 59 minutes
• on days of the week you specify, or every day, every second day, or every third day
• skip watering if it is not needed by connecting a soil moisture sensor (I have not done that).

The best time of the day to water gardens is early in the morning at sunrise.  At that time of day water that splashes onto leaves does not cause leaves to burn because the sun is not hot enough yet.  Water on leaves evaporates soon as temperatures rise in that early part of the morning.  This means that chances of mildew and other diseases are minimised.  I love gardening, but I simply never am in my garden that early in the day.  It would suit me to water in the evening, but that is not the best time to do it.

With the automatic watering of my hothouse working properly, I decided that I was going to try and improve irrigation of other parts of my garden.  I wanted to achieve three things:

1. Water most or all of my garden early in the morning
2. Have permanent hose connections so I no longer constantly connect/disconnect hoses leading to wear and tear on my connectors and leaks
3. Most importantly, minimise the time I spend watering my garden

My first experience with a Gardena watering unit had been good, so when, during a visit to a property near Kingston, owner Mary showed me what she does with the next step up from the Gardena tap timer I had, I was immediately interested.

After finding out about the system and spending time working out how this could work for me in my garden I bought ..........

On the left you see a Gardena Automatic Water Distributor (1197) - purchase price around $A90
On the right is a Gardena MaxControl (1834) tap timer - purchase price around $A100

The tap timer (on the right) has the same features as the one described earlier, but you can set up not just one, but up to six watering schedules.  The water distributor (on the left) is a clever box that distributes water it receives from the tap timer to one of up to six hoses that can be connected to it (in the photo only 3 hoses are connected).

The photo below shows where and how I installed the two boxes:

Tap timer and water distributor in a shady spot so they are not blasted by the sun

The system works as follows:

• The tap timer is attached to the tap, which is open permanently.  
• A hose runs from the tap timer to the water distributor.  The tap timer allows water to flow to the distributor for up to six times and durations that you program into the tap timer.
• At the other end of the water distributor you connect up to six hoses.
• The first time water reaches the water distributor it will go to hose 1.
• When water stops flowing, the distributor switches over to hose 2 and next time water arrives, it goes into hose 2.
• The process is repeated until water has gone through all six hoses, or fewer than six if, in my case, the system is not fully up and running yet.

Initially I wondered why these two gadgets were not combined in one box, but then I realised that you can have a long hose from the tap timer to the water distributor and position the water distributor where the six hoses coming out of it will be the shortest.  It suited me to have the water distributor on the ground right under the tap timer.

The first time I tested this with just a few minutes of irrigation to three areas of my garden I was excited when everything worked according to plan.  It was a joy to watch it in action, especially when I realised how much time it was going to save me in future.

Yes, you need to put some planning into this.  Here are two examples of what is possible with this tap timer and water distributor:

In these examples I put the recommended five minutes between irrigations so the distributor box knows an irrigation has finished and has time to switch over to the next hose.  Through a little window on top of the distributor you can see a number.  It is the number of the hose that will receive water next.

No, you can not water two areas at the same time.  If you like to do that, put them on the same hose!

The tap timer allows you to enter whatever irrigation days, times and durations you wish, but if they clash, it chooses one and ignores other conflicting ones.  My aim will be to keep it simple so I understand what I am doing, and can keep an eye on things until I am confident it all works fine.

And guess what: if you connect the hose that leads to garden area 2 to outlet 1 on the water distributor things will not work as expected!

No, you don't have to have six different hoses and garden areas to make this work.  I have it working with three at the moment.

No, you can't buy the same system for, let's say, just three hoses.  In the Gardena range there is only the six-hose version at present.

I did not mention irrigation methods (drip or soaker hose or overhead sprinkler or ... ) because you can use whatever you like.  This system transports water through hoses at times and durations determined by you and it does not matter what irrigation method you use at the end of those hoses.  Each can be different, and hose lengths can vary too.  As with all irrigation, if you make lines too long, water pressure at the end of lines will be poor.

An extra feature of this 6-schedule tap timer is that in summer you can set it to 100%, but at other times of the year, when less water may be required, you can change the percentage to, let's say, 80%, and then watering duration for all six areas of your garden is 20% shorter.  Watering can be suspended all together (for instance when there has been rain) by setting this number to 0%.

You can make the system even more professional by adding soil dampness sensors or rainfall sensors that you can buy from Gardena.  If they sense that watering is not necessary, the tap timer skips watering.  If you installed sensors, you could be away, and watering automatically would be switched on and off, depending on rain fall.

I think it is all brilliant, and most home gardeners will find the financial outlay manageable.

Thank you Mary for making me aware of it all.

As I said before, this blog post is not an ad.  Its aim is to show you what is possible with today's technology.  There may be other brands that do an equally good or even better job.


A system connected to mains power

The Gardena water timer system described above uses one 9 Volt battery in the tap timer. The water distributor purely works on pressure and does not need a battery. I find that one 9 Volt battery lasts me at least one season. To avoid a situation where dead plants tell you that your automated watering system stopped operating some time ago because the battery ran out, it is probably best to replace the battery at the start of every irrigation season.

When our group visited her food garden, Margaret showed us her automated watering system that is connected to mains power. When her house was built she had a nifty C-Bus system installed with a panel that controls all electronics in and around the house via a panel in her kitchen (see photo below).

One of its uses is to automatically irrigate six areas in her garden.

A power line and a water pipe go underground to six carefully chosen spots in her garden where a valve called a 'solenoid' (small black box above) opens and closes when told to do so by Margaret’s watering schedule.

You don't need to have a C-Bus system.  You can buy a mains power operated tap timer to set your watering schedule.  Solenoids have been around for a long time and most of them are very reliable and long-lasting.

The advantage of a mains power system is that you don't have to monitor battery use and never have to replace batteries.  The disadvantage is that you need to have 12-volt power lines dug into your garden and be aware where they are so you don't damage them when digging.

Now, two years later (March 2018)  

After writing this blog post I bought a second 6-schedule tap timer and water distributor of the same brand, and have used these two timers and distributors ever since, with complete satisfaction.

I now only manually water pots and spots that can not be reached by the irrigation, and that is an easy enjoyable task.  All the other irrigation is done automatically early in the morning.  Over time I have fine-tuned irrigation times.  I switch the timers off after rain, and then go 100% again a few days later.  As the seasons turn, I increase or decrease irrigation times.  It is all just a matter of keeping a little spreadsheet on my computer and adjusting times on the timers, not being in the garden for hours to keep it all watered.  I love it!

The 1-schedule timer described at the start of the blog post I no longer use, as I found it too limiting.  I would now recommend that people buy a timer with more than one schedule, because, once you have experienced how much time automated watering saves you, you will want to do it for more than one area of your garden.

Above I said that the aim is to show you what is possible with today's technology.  Well, today's technology, two years after writing this blog post, has progressed.  If I wanted to install a new automated watering system today I would still buy the same water distributors, but I would buy an Australian designed timer that is the next-step-up in technology.

Introducing .... LinkTap.  With LinkTap there is no need to keep a little spreadsheet on your computer and then go into the garden to manually change tap timers, you do that with an 'app' on your mobile phone.  With the app you set up irrigation schedules and change them when needed. Your LinkTap timer then changes its irrigation schedule accordingly, automatically .... wherever you happen to be in the world at that time.

The system consists of a LinkTap gateway that is inside, connected to your modem/router, that links LinkTap web site, and a LinkTap water timer, which is connected to your tap (see photo above).

The gateway is inside, connected to your phone line, and powered via an USB adapter that is included in the package.  The water timer is outside on your tap, and battery operated.  The distance between gateway and water timer can be greater than WiFi would allow because LinkTap uses a more powerful wireless technology.

When you are away from home, the app on your mobile can tell you what the weather forecast is for where your LinkTap devices are.  After checking the forecast you can switch your irrigation off or irrigate less if good rain is forecasted.  LinkTap also provides the option to do this for you automatically.

It is irrigation technology one step up from the Gardena water timer described above.  I am not going to replace what I have right now, but if I started from scratch, I would definitely purchase LinkTap timers.  LinkTap specialises in high-technology tap timers, and does not also make water distributors, so I would still use Gardena water distributors.

A few more details of the LinkTap water timer ...

• Very easy to set up and program
• Very flexible re watering days, times, and durations (up to 100 watering schedules per day)
• Can be programmed via a mobile app or via the internet with a web app on a PC or Mac
• A wireless soil moisture sensor that feeds info into LinkTap is being developed (March 2018)
• First water timer + internet gateway $A145.  Extra timers cost $A95 (prices March 2018)

Find out more about LinkTap at  https://www.link-tap.com/#!/ 


But don't be fooled by all this wonderful technology .....

One early morning with blue skies and no rain during the night I got up, looked out of our bedroom window and noticed that the concrete path to our clothes line was entirely wet.  Knowing that the irrigation had been on in that part of the garden at 5am, I decided to check.  I found that the terminator (the 'end bit') at the end of a drip line had been blown off.  All the water had flown down the concrete path.  Nothing had been irrigated, except the lawn down the path, which was soaked.

Moral of this story is that you can have a high-tech automated watering system that you can adjust while being at the other end of the world, but don't blindly trust it!  Install it, enjoy it, cherish the time it saves you by watering everything automatically, but do not trust that everything will always work without a watchful eye!


You can find more information about irrigation methods on this blog at   http://foodgardengroup.blogspot.com.au/search/label/irrigation )