Organic Hydroponics

It's been a while since we got into organic hydroponics but nevertheless let's keep this page active.
Hydroponics refers to the growing of plants without any soil or soilless gardening. Plants are grown in water to which a nutrient solution is added. We are in the process of developing a prototype making use of recyclable polystyrene containers and buckets. As a nutrient solution, we are using compost tea that we have "brewed" from the organic compost we have made. It is too early to establish if it is a success but so far results seem promising. If we can get it to work we will expand the system using larger polystyrene, recycled PVC piping, and other recycled containers. This is a very low-cost system that can provide opportunities for people in poor communities to produce their own food. Vegetables that are typically grown in hydroponic systems are lettuce, tomatoes, herbs, and cucumbers. People have even succeeded in growing hydroponic watermelons! So the possibilities are endless. We have managed to grow lettuce and tomatoes successfully using compost tea as a nutrient solution. We need to experiment a bit more. Once we are satisfied we plan to expand the system.

Tomatoes and lettuce are grown in a simple hydroponic system.
(This was many moons ago in our backyard.)

Lettuce is grown in a modified PVC container.

How to

These are very simple systems and it works very well. The basic requirements are a water-tight container, either a floating system or a lid with holes for the container, an air pump, and the nutrient solution. For the nutrient solution, we use composted tea we make ourselves. You need an air pump to add oxygen to the water for the microorganisms in the nutrient solution (compost tea) to survive. The containers are called netting pots and have slots in the sides and bottom to allow for the absorption of water, and for the roots to grow through. We use Hydroton to support the plants in the water. Hydroton is clay pallets that are water absorbent and do not rot. One does not need netting pots or Hydroton as this can be replaced by suitable plastic containers and stones for support. Both netting pots and Hydroton are not easily commercially available, especially where we are staying. The root systems of most vegetables will very soon fill up the entire container as it grows so vigorously in compost tea. So the bigger the container the better. We change the water about every two weeks. This excess water goes to the rest of the vegetable garden. There is no wastage. We are still experimenting to find the correct water/nutrient solution ratio for different plants. We have added taps at the bottom of the containers to allow for them to be drained easily. Removing the lid every time to replace the water disturbs the plants, especially tomatoes as the plants tend to get very heavy. Roots systems of tomatoes are also enormous. Looking at their root systems one understands why tomatoes are so thirsty. We fill up the container by just pouring the water onto the lid and it runs through the containers. As easy as that.

These systems can easily be done at home, and it is sustainable. This is what you will need;

* A container.
* Good quality compost.
* Clean water.
* Air pump and housing similar to those used to aerate a fish tank.
* Vegetable Seedlings.
* Netting pots or any pot that will allow water to reach the root system of the plant.
* Clay pebbles or gravel to stabilize the seedlings.

Here is the "recipe": Take the compost and put it in a stocking. Submerge the stocking in the water for about two days where after it must be removed. Start aerating the water once you put the stocking in the water. Plant your seedlings in the pot and add either the gravel or clay pebbles to stabilize the seedlings. The container should be filled up to the level where the entire root system of the plant is covered in water. After about 3 days the water should have the color of very strong tea, and it should be clear. If the water stays murky rather change the water again. The water can be changed after about two weeks. Carefully watch the plants. After about two weeks you should have a very good indication that your system is working or not.

More Resources

Want to know more about compost tea, the organic alternative to plant nutrition? Find more information here

Acres USA Following are two articles that give insight into the use of compost tea. These articles are provided courtesy of Acres USA.

Compost Tea - Just What The Doctor Ordered, by Mary-Howell R. Martens. "While chemical pesticides work by killing microorganisms, both the pathogenic and the beneficial ones, compost tea works on a very different principle. Dr. Ingham explains that when compost tea is sprayed on a plant, the leaf surface is occupied by beneficial organisms, forming a physical barrier against the pathogenic species and providing a competitive environment in which the pathogenic species lose out. Additionally, compost tea stimulates healthy plant growth as a foliar nutritional source, helping the plant to further resist attack. Read the full article here...

Compost Tea - Promises and Practicalities, by Elaine Ingham, Ph.D. "There is great interest among sustainable growers about the use of compost teas for increased crop health and fertility. Years of research and results in the field have demonstrated the power of this technology, which is growing in popularity. In this article, we will examine the nuts-and-bolts of compost tea — how it works, how it’s made, and what to look for in a specific tea." Read the full article here...

Read more about our organic food gardens here