As per Wikipedia, Aquaponics refers to any system that combines conventional aquaculture (raising aquatic animals such as snails, fish, crayfish, or prawns in tanks) with hydroponics (cultivating plants in water) in a symbiotic environment.
I got introduced to this topic about four years ago. I was wondering how it works and what are its mechanics. I read about it and created a couple of mini-systems based on what I learned. The results were amazing as I was able to grow herbs and pothos plants using the systems I built, attached to the aquarium.
Let us look at aquaponics in little more detail. There are two systems combined to achieve the goal of growing plants with less water. At the same time, this also helps to grow these plants organically. This is because you do not need to add any fertilizers. The water from the fish tanks contains the nutrients for plants. These plants are not grown in soil. They are either grown in clay pallets or some other medium or on the water surface with roots hanging in or just above the water level (that depends on what is your aim and what is your budget.).
I have set up small aquaponics systems successfully. If you want to set up on a larger system than a tabletop one then you have to look at the grams of excreta you are getting from fish and the area of your grow beds. Even the type of plants you want to harvest matters. I may write some in-depth articles about the math and the equilibrium between the type of fish and the plants.
Until now I spoke about the mechanical parts of the aquaponics system. There is a chemical component that is the backbone of this system. It is called the nitrogen cycle. The simplest way to explain this is that the fish eat the food then it produces excreta. Excreta is converted into plant food by special bacteria. Plant food is taken up by the plants. This cleans the water for the fish. If you want, you can read in detail about this Nitrogen Cycle here.
Types of the aquaponics system
There are different types of aquaponics systems, but the following three are the most common ones:
Deepwater setup is also known as raft system. It uses rafts of foam above the water. The plants are on the raft with the roots hanging below which are submerged in the water. The water is coming from a fish tank. This water is filtered to get rid of any solid waste. Then the water is returned to the fish tank.
Nutrient film setup:
This setup uses a tube, like PVC pipe to draw water from the fish tank and the water runs through another set of PVC pipes that are wider. There are holes drilled in this pipe on top which accommodate plants or planters with plants in them. These planters do not use soil, instead, they use some other material like clay pallets, or rock wool, etc. This is a great system for limited space, as this setup can be done either hanging from the ceiling or on the walls. This can also be set up vertically or horizontally. This setup is usually ideal for plants that do not need much support such as leafy greens.
Nutrient Film Setup
Media bed setup:
In this setup, plants are grown in a media like clay pebbles. This grow bed is then either placed beside the fish tank or on a shelf above it. The water is drawn from the fish tank using a pump and a tube or PVC pipe which fills the grow bed to water the plants. The plants take the required nutrition from the water and it is cleaned to be used by the fish. This water is then returned to the fish tank.
How to set up a mini aquaponics system
It is amazingly easy to set up one of the systems for herbs. You can have a small fish tank with light for the fish and aquarium plants. Then you need a grow bed. For this, you can get a small plastic basket just about the width of your fish tank. Fill it up with some medium, preferably clay pallets. Now run a tube or a PVC pipe from the water pump in your aquarium to the grow bed. Make sure you have a drain set up from the grow bed to the fish tank. You can either run the water two to four times a day or you can get a timer to automate it.
As you can see the aquaponics system is not only easy to set up, but it also does not need any artificial fertilizers for the plants or fish. It is all-natural in its true sense. This system is scalable and can easily adapt to how big you want to make it. As mentioned, I have tried it on the mini scale for desktop. It can be scaled to fit for your backyard or even for your greenhouse or a larger open field.
The other system widely used by many farmers is the Hydroponics system. It uses chemical fertilizers which are labeled as organic fertilizers.
Why use aquaponics to grow food?
- The aquaponic system needs no fertilizers. This saves a ton of money for the farmer. If you are growing food on small scale for yourself then you have organic food available to you year-round.
- This system uses much less water than the conventional way of growing plants. As per some, it uses up to one-tenth of the water used otherwise.
- The aquaponic system reduces the time required to maintain and clean the fish tank. If you set up the system as I mentioned above, then you rarely need to do any maintenance. I just add some snails to clean any algae growth in the fish tank. You just need to add water as required since the water evaporates.
- The mini-systems I am talking and explaining about are usually meant for countertops. This makes the herbs and other vegetables readily available to you. You can grow them in the kitchen, living room, bedroom, or anywhere in your house.
- The growth of plants is much faster with an aquaponics system as opposed to regular farming.
- As mentioned earlier the system is scalable and can be meant for a small family or a community.