Plants, Fish, and a Few Beneficial Bacteria

Today’s farmers are continually innovating when it comes to new methods of growing and raising our food supply. Aquaponics, a process which allows producers to raise and grow both a protein and vegetable crop simultaneously, has seen an increase in popularity.

Aquaponics is a combination of aquaculture – raising fish in water – and hydroponics – raising plants in water. Plants grown in a hydroponic or aquaponic system are not grown in a traditional method using soil. Instead, the plants receive their nutrients directly from the water they are grown in. An aquaponic system creates a symbiotic relationship between the fish, plants, and beneficial bacteria.

The only input into an aquaponics system is fish food. After the fish eat their food, they will excrete waste. This waste contains ammonia, which in sufficient quantities can be toxic to both fish and plants. Beneficial bacteria that naturally exist in the water prevent the toxic environment by breaking down the ammonia to nitrites and then to nitrates. The nitrate-rich water is then circulated to the plants, providing critical nutrients the plants use to grow. As the plants consume the nutrients, they help to purify and clean the water for the fish. This system forms a complete circle, as each organism helps the next, creating optimal growing environments for all.

Food is grown and harvested year-round in an aquaponic system. Even in the cold Wisconsin winter months, a greenhouse maintains a consistent temperature for the plants to grow. Additionally, water is circulated 24 hours per day, resulting in continuous production of both fish and vegetables.

The varieties of plants and species of fish that are able to be grown and raised in an aquaponic system vary. The deciding factor are the temperature and pH needs for each organism. The fish and plants should have similar needs, and although a compromise may need to be made, the closer they match, the more successful the system will be. Generally, warm, fresh water fish and leafy crops, such as lettuce, greens and herbs will do the best. Other examples of crops grown in Wisconsin aquaponic systems include kale, peppers, tomatoes, cucumbers, peas, and broccoli.

In Wisconsin, aquaponic growers raise many varieties of fish, such as tilapia, blue gills, yellow perch, and catfish. Superior Fresh, located in Hixton, even raises Atlantic salmon. Thanks to their innovations in controlled-environment agriculture, it is now possible to enjoy locally-grown, fresh salmon in the Midwest. Superior Fresh is not only an industry leader ideologically, but they also operate the largest aquaponic farm in the world. In 2019, they produced three million pounds of fresh leafy greens for consumers across our state.

Wisconsin is also home to Nelson and Pade, Inc., a leading supplier of aquaponic systems, training, and support. To date, their Wisconsin-made systems have been shipped to 27 countries and nearly every US state. Their company manufactures complete aquaponic systems for home, school, research, and commercial use. Each system is designed with efficiency in mind. On average, 12-14 pounds of vegetables can be grown for every pound of fish raised, thanks to their patented filtration system.

Aquaponics is on the rise across the United States, and farmers and processors in Wisconsin are certainly leading the way. Learn more about aquaponics in Wisconsin at superiorfresh.com (Superior Fresh) or aquaponics.com (Nelson and Pade).

*Images courtesy of Nelson and Pade, Inc.