Friday 26 August 2016

'Finally, let's get growing'

It took a lot of effort, money and time to get to this point so by now I had read a lot about lettuce being a good vegetable to start with; spinach I also found to germinate quickly and grow within a week.  My spring onions started to grow but oh so very slowly, so much so I would say they would probably have grown faster in the ground.  My radishes did not germinate at all.


Currently I'm experimenting growing flowers rather than vegetables.  A few thoughts behind this; firstly with vegetables you tend to have a dozen lettuces ready at the same time and end up giving them away whereas with flowers you don't need to 'consume' them all at once, you can transplant them in the garden.   With Brexit the cost of imported flowers (90% are imported) is likely to increase.

The nutrients

From what I have read the manufacture General Hydroponics three nutrient solution is considered the best especially for beginners.  I started with the litre bottles again bought from Amazon for around £10 each.  There is Flora Micro, FloraGro and FloraBloom of which you will need all three.  I noticed that the FloraMicro comes in both hard-water and soft-water with the hard-water version being three times as expensive as the software version.  My assumption is that purists of hydroponics say to use rainwater which is soft rather than tap water (no chlorine).  If you use tap water as I do it's suggested to leave it in direct sunlight for 24 hours to remove the chlorine.

Hydroponic purists also say not to use metal, sealants, and only food grade plastics in your setup.
Click here to continue reading on this subject.

feedchart is available from the General Hydroponics website which provides all the information you need.  I also found this video very useful as an overview.

You need to reduce the PH value of the water you are using to around 5.5 depending upon the plat you are growing.  I found that it's cheaper to buy the PH UP  and PH DOWN bottles together than just the PH DOWN on its own, which to be honest is the only bottle I have ever used.



The yellow device is called a PH Pen Tester which is around £10 from Amazon and is essential to check the PH of the reservoir water.  The hydroponics purists also recommend using a TDS Digital Water Quality Tester (the blue device).  This is a very useful video providing an overview into what TDM, PPM, conductivity and EC mean!

I haven't used my TDS meter simply because as soon as water passes through the clay balls the PPM reading goes through the roof makes it meaningless.  In a pure hydroponics setup where just water is used then it would be more beneficial.

Finally from a practical perspective using a large volume syringe makes life much easier when measuring the nutrient .  A recommendation I have seen is not to mix the nutrients together; instead reduce the waters PH then add each nutrient, one at a time to the water while mixing.

The temperature of the reservoir is important since warmer water absorbs less nutrient and oxygen this is why I buried my reservoir in the ground to keep the temperature constant and also use an aerator.  This is a very useful video on reservoir temperate.
Monitoring hydroponics

I originally set out to monitor and control my hydroponics setup using the Arduino however it soon became obvious that keeping everything as simple as possible is definitely the best idea.  I've now left growing down to Wilma and instead focused the Adrunio on monitoring the environment with multiple sensors.

I've discovered a fantastic website called ThingSpeak which enables you to send sensor readings from the Arduino, then you can graph and analyse data.


Click here to see the real-time hydroponics  monitoring in action!

Problem alerting

It's useful to log the environmental factors influencing the crop but it's even more important to know if there is a problem such as things are getting too hot in midday sun and you need to do something about it.  This is where I use a second really useful website called Prowl which pushes alerts to your mobile, tablet or computer etc.



About the Arduino environment

Just like the hydroponics setup there have been a number of versions of the Arduino design, originally with relays to control pumping (running via a 12v caravan battery), through to coupling of a Raspberry Pi 3 to provide monitoring, graphing and alerting - then ultimately superseded by ThingSpeak and Prowl.



The Arduino design running today simply collates sensor data and logs it to ThingSpeak.  In the 'control box' there is an electronic timer to control pumping cycles which are specific to the growing life-cycle of the plant, a complementary timer to switch the air pump on / off, and a home-plug to connect the Arduino to the Internet.  Further reading on aerating a hydroponics reservoir.

What's the Arduino is monitoring?
  • Environmental temperature
  • Plant temperature
  • Plant humidity
  • Reservoir temperature
  • Ground temperature
  • Arduino Temperature
  • Rain drop sensor alarm
  • Sensor failure alarm
Contact me if you would like a copy of the source code ;)
Version 3.0 - 'Third time lucky'

The PVC sheet concept worked much better than the flower troughs but it still continually leaked where the return hose ran back into the reservoir.  At this point I also started to get problems with the Arduino crashing when the water pump started.  My original goal was to remotely monitor the hydroponics setup using the Arduino and control it but I was now still struggling to even grow a single thing.  The pivotal moment came when one night all 30 of my seedlings were eaten by slugs!

Pests are indeed a very real risk to your hydroponics investment especially when you have the kit outside (with cost apportionment I was up to about £25 a lettuce at this point).  With experience I am now using a combination of stale larger, salt and copper tape, continue reading here.

So, I decided to cut my losses and go with the Atami Wilma 10 Pot Hydroponic Dripper System which cost me £97.98 from Amazon.  Thank God.

I also purchased a plastic cold-frame £31.50 to protect everything from the elements.  In the picture you can see the Arduino monitoring system (more on that later).  I also dug the Wilma into the ground for thermal stability.


Conclusion

I recommend buying a hydroponics system just so you can quickly get growing, then as your experience expands create your own system.  There are so many things to go right / wrong when attempting to build and grow initially.  If I had started with a purchased system I would have saved myself several months and a good few hundred pounds.


First results

From seed to a fully grown lettuce only took six weeks which was extremely satisfying (plus tasty) given the problems I initially had.


Version 2.0 - 'Back to the drawing-board'

I quickly discovered the clay pebbles continually became lodged in the pipes connecting the troughs which ultimately led to the problem where the first few troughs filled up with hydroponics solution and took a good 30 minutes for all ten troughs to fill and drain.  This posed a real headache preventing the reservoir getting pumped dry and burning the pump out.  The workaround was to pump for one minutes and wait for five minutes then repeat, ugh.



So v2.0 was a fundamental redesign whereby I removed all the flower troughs, leaking pipes that clogged with a simple PVC sheet lining the ground trough.

Lessons learned

At this point I was reminded about the laws of gravity.  

I had mounted the water pump in the relative safety of my garden shed which is next to the troughs with the thinking to protect it and be close to the Arduino control equipment (I'll cover this later).  By mounting it there it meant that as soon as the pump switched off water siphoned out of the pipe leaving the pump needing to be manually primed.  Cue max irritation.

The v2.1 design moved the pump under the reservoir which meant it never needed to be primed.

I also realised I needed protect the setup from the elements such as rain and debris so I purchased some grow tunnels.


Shopping list

  1. AmgateEu 30-Pack 2.8 Inch Mesh Plant Pot @ £9.90 Amazon
  2. 25 Litre Plastic Water Container Food Grade @ £10.58 eBay
  3. Kingfisher Transparent PE Grow Tunnel @ £7.28 Amazon
  4. GroDan Cuttings Rockwool Seeds Cubes 1 inch x 77 @ £11.97 Amazon

Version 1.1 - 'Optimise'

The plan was to remove the weakest link, the guttering.  I bought garden irrigation pipe used for hanging baskets so that the water from the pump would drip feed into each trough individually rather than gushing into each trough.  I soon found that this method works only due to mains water pressure, a small pump just can't create the necessary water pressure.

I abandoned that idea and instead used normal hosepipe linking the pump to trough number one, with connecting water pipes connecting subsequent troughs back into the reservoir, a bit like an overflow. This seemed such a simple idea I couldn't understand why after googling it I couldn't find anyone else who had done it (there is a reason!)





Lessons learned
  1. It was a nightmare to connect the troughs and pipes together especially as they are beneath the ground.  Getting one end in inevitably meant another pipe came out.  Even when using lots of silicon sealant I couldn't get a watertight seal which meant lots of expensive hydroponics solution was continually lost.
  2. Alas I didn't think about the reservoir size I actually needed so I just bought a food grade 25 litre container.  This an important point ensuring you have enough nutrients for the plants.
  3. Having ten flower troughs meant I needed over 90 litres of clay pebbles which not only added to the cost but also had an impact on the amount of nutrients needed (and ultimately the reservoir size).

Shopping list
  1. Canna 45L AquaClay Bag from @ £15.99 each Amazon
  2. 46m Micro Irrigation Watering Kit @ £12.77 Amazon
  3. VivReal 12V DC Submersible Water Pump @ £12 Amazon


Version 1.0 - 'Keep it simple'

In my mind I had visions of a simple Dutch Bucket design with a reservoir, pump and Arduino acting as the control.  I bought some flower troughs with holes in the bottom and guttering to return the water to the reservoir.





Lessons learned
  1. Although simple it was incredibly difficult to get a good gradient from trough one through to trough ten (yes ten troughs, what an idiot!) and back into the reservoir
  2. Dirt continually got into the water
  3. Putting the troughs in a trench however did keep them thermally stable with the rise and fall of heat in the summer.
My hydroponics project for beginners


About this blog

During 2016 I have been experimenting with hydroponics starting off as a complete novice to now being more accomplished.  This blog provides lessons learned, hints and tips for those starting out in hydroponics.  "I've already made most of the mistakes you are about just too!" - Mark Cunnell



What is hydroponics?

Hydroponics is a method of growing plants using mineral nutrient solutions, in water, without soil.

The concept surprised me having only ever seen hydroponics in Sci-Fi films but a bit of googling quickly proved just how popular it is from hobby enthusiasts and small holdings right through to huge commercial operations.  Equally surprising are its origins, rather than being Sci-Fi they date to circa 1627.  Wikipedia provides a great introduction into the subject, continue reading here.

You may well at this point be thinking "Yuk I'd never eat anything grown like that", well if you have eaten a tomato, lettuce, cucumber, basil....over the last few years you already have.  Hydroponics means you can grow more in a smaller area, faster, all year round and therefore at a greater profit.


Carpe Diem, Seize the day

Once I started reading around the subject I quickly became excited with the possibility of throwing in the day-job (sound familiar?!) and either setting up a small holding on cheap land or creating hydroponics kits commercially.

I quickly came to the conclusion that creating hydroponic kits is already highly automated especially at a commercial level, even setting up a small holdings the question soon became should I buy a kit or design and build my own - so, if I was going to do anything I first needed some experience.

A really interesting article in the Economist which discusses 'vertical gardening' opening up the possibility for huge yields even in cities.


Getting inspiration from YouTube