Can you imagine raising fish under your urban garden ? This is the proposal of aquaponics, to integrate fish farming to save 90% of water and eliminate, at the same time, the use of toxic chemicals. A system that is being developed for both private and industrial use.
The term aquaponics is derived from the combination of the words ‘aquaculture’ (production of aquatic organisms) and ‘hydroponics’ (production of plants without soil). It is a sustainable system for the production of plants and fish.
The system is as follows: the fish produce compost or fertilizer from the land, once they expel the waste of what they eat, rich in nutrients. In other words, people feed the fish so that they then feed the people. The circle of life.
Thus, the natural ‘fertilizer’ expelled by the fish is pumped to the top, where it is absorbed by the plants. At the same time, the roots purify the water when they remove these nutrients, which goes back down to where the fish are. In this way it is not necessary to introduce clean water every week.
This system can save up to 90% of water in relation to conventional agriculture and completely eliminate any waste that could be generated, since it is a closed system. Today systems of this type already exist both for home production and for industrial-scale production.
A home aquaponics system can be installed in an urban environment, in a free space of the house, on a balcony, which receives at least 5 hours of sun per day. Commercial aquaponics systems, on a large scale, are also easy to install. manage and the producer has little to control, both in crop and fish production. Vegetables, such as lettuce, can be harvested after four to six weeks of short cycle.
A technique with history.
The integrated fish and vegetable culture system technique actually reproduces the natural cycle of nutrients in any small-scale ecosystem. It is not something new today: aquaponics was already known and used thousands of years ago by civilizations as diverse as the Aztecs or the Chinese.
What fish should we use?
The fish used in aquaponics are generally tilapia, a species that is very hardy and capable of supporting high population densities. Although the truth is that the system welcomes all kinds of freshwater fish. Important: this system works best in hot climates;
What will we need?
To carry out this system at home, the following elements are necessary: a pond to raise the fish; a pump, responsible for transporting the water with the nutrients from the peaces upwards, where the hydroponic cultivation is located; gutters where we will plant our garden, a pipe through which the solution circulates and a filtering system so that the pipes are not obstructed.
As for the substrate that we will use in this type of orchard, it will be gravel that can cover different sizes. Irrigation must be continuous, drip irrigation systems and the like do not usually work well.
The best thing about aquaponics is that it is totally ecological, we already get a non-polluting fertilizer that is also totally natural.
Basic rules to follow in aquaponics.
By following some basic rules you will be able to set up and maintain your own system without problems.
- Very important the tank. Fish tanks are a very important choice in aquaponics. Any tank may work for you, but if you use a round tank with a flat or conical bottom, you will simplify your life, since they are easier to clean.
- The aeration and circulation of the fundamental water. Consider using water and air pumps to ensure your water has high levels of dissolved oxygen and good water movement so your animals, bacteria, and plants stay healthy. Use photovoltaic energy when possible, as any power outage can be fatal to your system.
- The quality of the water is crucial. Water is vital in an aquaponics system. It is the medium through which all essential nutrients are transported to plants and where fish live. There are five important water quality parameters to follow and control: dissolved oxygen (5 mg / liter), pH (6-7), temperature (18-30 ° C), total nitrogen and alkalinity of the water.
- You don’t have to fill the tanks too much. The recommended density is 20 kg / 1000 liters, which leaves a substantial growth area for the plants.
- No to supercharging. Feed the fish every day, but remove any uneaten feed after 30 minutes and adjust the next day’s serving accordingly.
- Choose and space plants carefully. Green leafy vegetables work very well in aquaponics, along with some more popular fruit vegetables, such as tomatoes, cucumbers, and bell peppers.
- Good balance between plants and fish. Having a safe source of plants and young fish is important, so be sure to factor in supply in the planning phase.
How to make a homemade aquaponics system.
Although in English, here you have a very complete manual on aquaponics.