For those who don't know First timer Hydroponics serie, please refer to the first I'ble I have written or to the early start of this collection of I'ble about my Urban Garden.
I am a first timer. What is below is the fruit of active readings of books, internet websites, conversations with some very passionate shopkeepers... So please, let me know if I did something wrong or if you have lessons learned to share ;-)
In this second I'ble about hydroponics I have build a DWC system. DWC stands for Deep Water Culture. This is a fairly old technique and widely used, from lettuces to flowers.
the topic of the I'ble is not to actually build a DWC but to track results and see how DWC is performing regarding other systems.
There is a very good I'ble about building a DWC system hacking IKEA furniture.
As I don't want to claim property of something which is not my design and as I think this I'ble is very good, I will let you go there and build your own as I did. In the next step I will explain you the little change, add-ons ect I have made according to my issues.
If it happens that you like this project, please share, favourite and vote ;-)
Step 1: What Is DWC?
Deep Water Culture is a method to grow plants in hydroponics.
Plants are immersed or just in contact of a nutrient solution put in a reservoir. The plants are in a soil-less net cup, either floating on the surface or in a container (I choose the second option for this I'ble but I will test the raft version soon).
On the above scheme, the system (a) doesn't require absolutely air stone and oxygenation of the nutrient solution as the plants have what I call areo-roots which can provide oxygen for the whole plant. The system (b) absolutely requires it as their is no other way for the roots to be oxygenated. In this I'ble we will make the (a) system.
DWC is a low cost and efficient hydroponic system.
Step 2: Build a DWC System (Ikea Hack)
If you like to see the whole I'ble about building such a DWC, please visit the project of rfernandes18
I have made minor changes to this project. Frankly speaking I hardly claim any major improvements...
I just had a line on the side to be able to see the min level of nutrient solution (min level is for me the level when the water just touches the containers)
Some lessons learned so far:
- After cleaning your clay granulates, especially if you had them one or two days in the water, small diameters segregates from others diameters. So take care to have all diameters in your containers when filling them up.
- Take extreme care when moving your plants from their germinating medium to the clay granulate. I might have been not soft enough
- I have used plants with 4 leaves. I think that it might be a good idea to wait a bit more as, a couple of hours after moving, they seems very weak.
I have planted 2 lamb's lettuces on each side.
At that point, I still had two major questions/issues:
- Do we need the water to be in contact with the containers?
- Do we absolutely need an air stone?
I have some answers to those questions (see next steps) but if you have any ideas/answers, please let me know.
Step 3: Vermiponics: Focus on the Worm Tea
As I told you in n°1, I don't like the chemical aspects of hydroponic. I am not saying that I will never try but I feel more confident in using organic and sustainable resources of nutrients. That's why I use worm tea.
I usually filter the tea and then just water my hydroponic systems from above, allowing any extra tea to go to the reservoir.
In this n°2 I'ble, let's speak a bit more about worm tea and why it is a good way to feed plants in hydroponic.
I will write a full I'ble about how to get true compost tea. The point here is to discuss what benefits you can expect from your compost tea.
The tea is obtained by brewing worm compost in water. The tea is then filtered off to make the fertiliser. It contains many minerals and nutrients and may be more importantly many helpful bacteria and microbes. this nutrient solution is alive and will enhance your soil and leaves if you use it as a spray. Worm tea seems to be an insect repellant but I have never tested this.
The compost tea is full of nitrogen fixing bacteria and others microorganisms who loves oxygen. So there is a benefit in oxygenating your tea to enhance its natural properties.
The organisms living in the tea also produce all kind of things incl. hormones, vitamins, nutrients, enzymes, amino acids and minerals. Those things are highly recommended for young plants. The symbiotic relationship between the plant and the microbes in the root zone make the whole system a wonder: when plants are feeding the microorganisms, they produce in return nutrients and micronutrients. In addition, they occupy the space leaving little room to unfriendly bateria.
If worm tea is a wonderful nutrient solution, you don't have a lot of risks of burning roots and plants if overused. That's the beauty of the tea.
There is a very interesting Wikipeida article about Vermicomposting (not only about tea... not really about tea... not at all about tea...)
Step 4: First Results: Difficult Start But Encouraging Facts
Three weeks later, my 4 lettuces are alive which is already a result in comparison to my wick system...
Really early in the project I have realized that my production of worm tea will be too small to feed all my projects. So i decided for this first round of experimentations about hydroponics to go back to a standard fertilizer. I have used a Bio Nova Hydro SuperMix, which is according to my local grow shop, very simple to use (I check that), very stable in water and powerful. I don't really manage pH and EC of the nutrient solution. I change water every 3 weeks as stated in the "Hydroponics for everybody" book. I don't supercharge my solution. I just use the lower level of fertilizer.
Next time I plant something in hydroponics I will use net pots. They are a much more convenient way to place correctly the roots without damaging them. They are super fragile and so important. I think I have not been careful enough so my lettuces have had a difficult start. But now they are doing better.
After a lot of thinking and reading I decided to buy a basic air pump. Oxygenating the roots seems to be one of the top way to ensure a sustainable growth of the plants. As I don't have electricity on my balcony, I plug the pump everyday for two or three hours through an open window.
If my plants are today smaller, with less leaves than their fellows grown in earth, I know that I am doing well with this wonderful design. I can see healthy roots reaching the surface of the solution. that's great.
We are early in the year so night are still fresh and the amount of light is not perfect. I guess the growing season is ahead of us!
I will post here some updates about this projects and upcoming results, and hopefully, harvests....
Step 5: April Update
We started our DWC system 4 weeks ago and as you can see the results are encouraging. Roots are showing up and the lamb's lettuces are growing fast.
Step 6: First Time Hydroponic Serie Summary
I have had 3 systems running in parallel but I kept only two of them.
In the summer I plan to grow other vegetables on my existing systems such as paprika.
This is a great endeavour for me and my sons. They love taking care of our balcony garden and I hope it will worth all that love.
you can find the 2 other projects here:
- the wick system
- the DWC raft system