Aquaponics is a combination of aquaculture and hydroponics-- cultivating both plants and fish by taking advantage of their natural cycles. In aquaponics,fish produce waste and the fishy waste-water from the tank is pumped to the grow beds where plants are grown hydroponically (without soil). The plants absorb the nutrients they need from the fishy waste-water while their roots filter the water --stripping it from ammonia, nitrates, nitrites and phosphorus, which is deadly for the fish.Then, the clean water is pumped back into the fish tank, and the fish dirty it up again with their waste. This cycle continues indefinitely.
Aquaponics is environmentally friendly. There are no chemical or fertilizers needed because it is based on natural cycles that convert the fish waste into fertilizer for the plants. Also, aquaponics uses about 10% of the amount of water used in conventional farming, as water is recycled in the aquaponics system through a pump, instead of being continuously sprayed over a field. Furthermore, as aquaponics is a form of back-yard gardening, it decreases the need for imported fish and produce, which decreases the amount of gas used in transporting them. But most rewarding of all is being able to eat and enjoy your very own sustainable produce and fish.
Step 1: Materials
Here is a basic list of materials you will need to construct your own aquaponics system.
Tank We used a horse tank that was already in the barn. Other possible things to use for the tank would be IBC crates, barrels, or actual fish tanks.
Pump The most important thing--besides the fish and plants. The pump will pump the water from the fish tank to the grow bed. We obtained our pump from a thrift shop.
Grow beds Again, we used materials that were lying around in the garage. For our grow beds, we used two divided kitchen sinks (with the faucet removed), to provide a total of four grow beds. Also, we drilled holes in the grow beds so that the water would be able to drain back out into the fish tank once it is full.
Siphon The siphon will divide the water from the pump into each of the four grow beds. We simply used a PVC pipe and drilled four holes in it so that the water would flow into each of the grow beds.
Gravel We used drainage gravel (also known as red scoria) as the medium for our grow beds. This is not the same type of gravel as the gravel in the road. It is basically crushed volcanic rock and is reddish in color. It is cheap: about $40.00 per cubic meter (ie. $20.00 for a 6x4 trailer load) and is coarse, so the water drains well. Because the gravel is small and coarse, there is way more surface area for the bacteria and roots, which means there is more room for the good stuff to happen!
Plants Most normal garden vegetables work well with aquaponics, except for root vegetables (like potatoes and carrots). This is because the roots do not have any soil to attach to. Common plants grown in aquaponics are tomatoes, okra, spinach, lettuce, cabbage, herbs, cucumbers, and even flowers.
Fish Tilapia is the most common fish used in aquaponics because they are available year round, they are easy to raise, and they taste delicious! Other fish that you can use are catfish, trout, salmon, and perch. However, you have to make sure you account for the temperature that these fish live in. For example, we could not use tilapia in an outdoors aquaponics system in Kansas during the winter because they cannot survive in water below 70 degrees Fahrenheit. To start our aquaponics system, we are using goldfish, which are really cheap. In our tank, we have about a dozen goldfish. Also, we put some carp that we caught at the lake into the tank. Once the nitrogen cycle levels out and our system is regulated, we will switch over to catfish from the lake so we will be able to eat both the plants and the fish.
Tools You will also need tools to drill holes.
*Note- you may not need all of the listed materials, or you may need additional materials based on your needs. Not every aquaponic system will be alike due to differences in goals, climate, and availability of materials.
Step 2: Putting It All Together
First, fill the tank with water and put the fish of your choice in. We used a combination of lake water and normal hose water. Again, we used goldfish and carp to start.
Before you place your grow beds on top of the tank, drill a small hole in the front, so that the water will be able to drain out of the grow bed and back into the tank.
Then place your grow beds on top of the tank and make sure they are secure and firm.
Fill the grow beds with gravel.
Attach the pump to the siphon so that the water will pump through and will be evenly distributed to each of the grow beds.
Plant your plants into the grow beds.
Allow time for the nitrogen and ammonia levels to be evened out and enjoy your homegrown fish and produce!!
Step 3: Future Plans/Challenges
As we are still in the set up phase of our aquaponics system, we have many goals for it.
Experiment It will be fun to experiment with different plants and fish cominations. Which fish/plant combination will best fit our needs? Strawberries and tilapia seem like a promising combination
Winter Woes As our aquaponics system is outdoors, we will need to either move it indoors or make sure the water is heated during the winter months. Obviously, aquaponics won't work if the water is frozen solid. (Ice fishing, maybe?)
Presentation Our aquaponics system was made almost entirely with materials lying around in the garage. While this made the project very cheap to make, it does look slightly red-neck. Once we have the system up and going, we will work towards making it look more professional (although, if it is working well, we might just embrace it's red-necknes).
Participated in the
Instructables Green Design Contest