Related Articles: What Is An Aquaponic System?
An aquaponics system allows you to grow your fish and plants together using just a single system. So how does an aquaponic system work? It mimics how fish and plants interact naturally, and this growth system doesn’t produce any toxic waste. It doesn’t need chemical fertilizers and other nutrients for plants. The only additives you need are the natural chemicals you need for the water and the food you need to feed the fish.
It’s best to look at it as a cycle involving the tank for the fish and the grow bed for the plants.
- Let’s start with the fish in the tank, which you then feed regularly. Once they have fed, the fish then produces waste that’s rich in ammonia. This waste is toxic for the fish, and it’s bad for them if you allow a buildup of ammonia to accumulate.
- The fish also breathes in oxygen from the water, and they breathe out carbon dioxide.
- The water is then moved by the water pump into the grow bed where your plants are.
- The plants then absorb the carbon from the carbon dioxide in the water. That leaves the oxygen remaining.
- In the grow bed, you have naturally-occurring bacteria. These bacteria convert the ammonia from the fish waste into nitrites, and to nitrates.
- The plants then also absorb the nitrates as nutrients.
- The water is then pumped back into the fish tank, and they’re once again good for the fish. The ammonia that’s toxic for the fish is gone, and once again the water is full of the oxygen that the fish need to breathe. Then the cycle continues anew.
Different Styles of Grow Bed Designs
You have several options regarding how you want to set up your grow bed. Here are 2 of the most common options:
- Floating raft. In this setup, the fish tank lies under the grow bed. The water pump moves the water from the tank up to the grow bed, where there’s a high water level. The water moves through a bio-filter, which converts the ammonia that’s in the water into nitrates. The plants here are floated in the water with foam. You also have air stones that provide aeration for your plant roots.
- Flood and drain. Again, the water is pumped up from the fish tank below to the grow bed above. The grow bed is made up of expanded clay balls or gravel where the bacteria proliferate, and the roots then extract the nutrients they need from the water. A siphon arrangement controls the water level in the grow bed, and it alternates between flooding and draining the grow bed. This allows the water to circulate through the system on a regular schedule. Gravity then leads the water back into the fish tank.
The flood raft design is mainly used for commercial setups. In aquaponic backyard systems, the flood and drain design is the most common. You’ll need more research to determine the proper balance between the number of fish and the number of plants, as the balance depends on the species you choose for your fish and plants.