When you grow your own food in an attempt to sever ties with big agriculture and the mega grocery stores that sell their wares, you sometimes have to get a little creative. The traditional way to produce food is to put seeds in the dirt, water them, allow them to get sun, and wait for your food to grow. But, there is another way to go about getting your vegetables: hydroponics.
What is hydroponics?
Hydroponics is a type of hydroculture. Hydroculture is growing plants without soil. In hydroponics, plants are grown in water with a nutrient solution that provides the minerals that they normally get from soil. Hydroponically grown plants may have their roots directly in the water or anchored by an inert medium like gravel, diatomaceous earth, clay, perlite, or coconut husk.
The discovery that eventually led to hydroponics occurred in the 1700s. Scientists found that plants absorb nutrients as ions dissolved in water. When plants grow in soil, the nutrients are only absorbed by roots when there is water available. The soil itself contributes nothing to the process of absorption. For this reason, just about any plant can be grown without any soil at all as long as adequate nutrients are provided in the growing medium.
What are the benefits of growing hydroponically?
As with any gardening technique, there are both pros and cons to hydroponics. On the plus side:
- You need no soil to grow plants this way.
- Water can be recycled and reused in hydroponics, so you need far less water overall than you would use for traditional gardening.
- You can control the amount and ratio of nutrients that the plants get.
- Pests and diseases are less of a problem, because they often persist in soil.
- You will not release any pollution into the soil via fertilizers.
- Hydroponically grown plants grow faster and provide a larger yield than soil-grown plants. This may be because the roots in hydroponics have more access to oxygen, which helps them grow more and absorb nutrients faster than those in soil. Another idea is that because the plants need not use energy to find and break down food, they can use that energy to grow.
Are there any disadvantages to using hydroponics?
The advantage list outweighs the disadvantage list, but hydroponics is certainly not a perfect technique. To get started in hydroponics, you will need to invest time and money in equipment and learning how to use it. You also risk killing your plants quickly if anything goes wrong. Out in the garden, your plants have a better chance of survival, but in a hydroponic set up, they are completely reliant on you to get it right. Although in general hydroponic plants are less susceptible to diseases and pests, they are vulnerable to fungal infections because of the moisture levels.
Should you use a solution culture or a medium culture?
There are two main ways of growing plants hydroponically: with a medium on which the roots grow, or without. Without a medium, the roots of the plant go directly into the nutrient solution. Solution culture can be further broken down into static and continuous-flow types. For a static culture, the plants grow in containers full of nutrient solution. These could be glass jars, plastic tubs, buckets, or some other type of container. The roots are partially in the nutrient solution and partially exposed to the air to ensure they get enough oxygen. For a continuous-flow solution culture, a pump circulates the nutrient solution so that it constantly flows past the plants’ roots. Although the equipment is more complex, the continuous-flow method produces a greater harvest.
Medium culture hydroponics involves anchoring the roots in some type of inert medium. This technique uses the capillary action of the medium to get the nutrient solution to the roots. In other words, the medium absorbs the nutrient solution and transfers it to the roots. Advantages of using a medium include giving the roots a structure on which to grow, providing the roots with adequate oxygen, and reducing the chances of root rot developing.
What are the choices for a growing medium?
You have many different choices when it comes to selecting a medium for hydroponics. They differ in terms of porosity, ability to absorb water and nutrients, water retention, and cost.
- Expanded clay aggregate. These are baked clay spheres or pellets that are inert and do not have any nutrient value in themselves. The pellets are lightweight and porous. They are sustainable because they can be sterilized and reused.
- Coconut fibers. The fibers from the outer shell of a coconut make a good growing medium for hydroponics. It is natural and contains a fungus that actually helps roots grow. It can store and release nutrients to the plant roots as well.
- Rock wool. Also known as mineral wool, rock wool is the most commonly used medium in hydroponics. It is made from molten rock that is spun into fibers. It is very efficient at absorbing water and nutrients, but it is a suspected carcinogen.
- Perlite or pumice. Both are volcanic rocks that are light and porous and absorb water and nutrients well.
- Gravel or sand. Gravel and sand have the advantage of being very inexpensive and easy to find. On the other hand, they are very heavy and dry out easily. Sand must be sterilized between uses.
What about the nutrients?
To grow your hydroponic plants, the nutrient solution is essential. You must provide the same nutrients that are found in soil. You can create your own solution by mixing chemicals into water until you get the right ratio, but this is not easy. You need to find the right recipe, the ingredients, and mix them together correctly. It is possible to make your own, but it is much easier to by a premade nutrient mixture from a hydroponics supply store. These typically come in a concentrated form, and you measure a certain amount into your water.
Another important aspect of your nutrient solution is the pH level. For hydroponics, the water should be between 5.8 and 6.8, with 6.3 being the ideal reading. You should test your solution weekly with a simple pH meter or testing strips and adjust accordingly to maintain the right level of acidity.
Your nutrient solution is just the right environment for algal growth. To avoid it, use a container that is opaque, or wrap a clear container in black tape to keep light from penetrating the water.
Should you make or build your hydroponic system?
That depends on your ability level, your tool availability, and the amount of time you have to spend on a project. If you have the time and the inclination, make your own. You can find plenty of designs and directions for building a hydroponic system online and in books on the subject. By making your own, you get to control every aspect of your system and save money. You can use spare bits of materials you have lying around to construct an inexpensive system. Of course, if you can’t even make a birdhouse, you probably will struggle to build your own system. Hydroponic suppliers are easy to find, and, depending on where you live, there may even be a brick and mortar store not too far from you. At the least, you should be able to find a variety of system for purchase online.
©2012 Off the Grid News