Tucson, AZ Aquaponics Startup Keeps it Local, Grows Fish and Produce in the Desert
February 25, 2013 | Pamela Ellgen
The idea of eating only locally-grown, seasonal food sounds appealing. Until you move to the desert. With an average annual rainfall of less than 13 inches, Tucson, Arizona is somewhat less than hospitable to traditional, soil-based agriculture. And fish? Forget it.
But, it was not the land that drew Stéphane Herbert-Fort to the Sonoran desert. It was the sky. He came to the University of Arizona to study astronomy and graduated with a PhD in 2011. Midway through his grad studies, however, he unearthed a deeper ambition than life as an academic.
“As a longtime fan of sustainable technologies and organic gardening, I wanted to join the two and make an impact on urban agriculture in Tucson. It was the perfect time for a change. Aquaponics fulfills my passions: to grow as much food as possible, simply and sustainably.”
In April 2011, Local Roots Aquaponics was born. Stéphane and a couple of partners now grow a wide variety of fresh produce and fish in their recirculating aquaponic systems, which are designed to mimic a balanced ecosystem between fish, plants, and beneficial bacteria. Over the last two years, while Local Roots has been in its startup phase, Stéphane diversified the business model to include workshops, consulting, and building aquaponic and pond systems for others.
“The recent recession has everyone thinking about efficiency,” Stéphane says. “Couple that with a growing desire in people to choose a more sustainable, local diet, and aquaponics really hits those on the head. Over the life of an aquaponic system, it is the cheapest and among the most sustainable ways to farm.”
While startup costs can be pricey, maintaining an aquaponic system costs relatively little in comparison to soil-based agriculture, hydroponics (raising plants in water with added nutrients), or aquaculture (raising fish alone). Typical expenses, such as irrigation and hydroponic fertilizers, are minimized or eliminated with aquaponics due to the symbiotic nature of the operation between fish and plants. Moreover, by recirculating water that is not used by the plants, aquaponic systems can conserve over 90 percent of the water traditionally used in soil-based agriculture and aquaculture.
In aquaponics, what’s good for the bottom line is good for the earth as well. With hydroponics, fertilizers build up over time, requiring water to be changed periodically. Similarly, with aquaculture, water must also be changed periodically to address ammonia, nitrite, and nitrate buildups.
“Combining hydroponics and aquaculture cancels out the downsides of each,” Stéphane says. “Through beneficial bacteria in the media — lava cinders in our case — the ammonia generated by fish is naturally converted into nitrates that are used by plants for vigorous growth. The plant roots filter the water for the fish, and the cycle repeats.”
Simplicity governs the practices of Local Roots, and the farm grows year round in Tucson without the use of greenhouses. During the hot summer months, it uses shade structures to reduce the possibility of overheating. The farm also employs constant-flood, constant-flow media systems as opposed to flood and drain. The former has an evaporative cooling effect on the grow beds, a nice benefit in the sweltering Tucson summers.
Local Roots also seeks to close the food-waste loop. They’re moving away from commercial feed toward composting local food wastes with worms and grubs, which eventually become fish feed, along with other locally-grown feeds, such as duckweed, moringa and others.
“The idea is to try to keep as many of the nutrients as local as possible; use local food waste to produce local fish feeds, to grow local produce, to generate more local food waste,” Stéphane says.
When he first started exploring aquaponics, the idea of growing fish in the middle of the desert captivated Stéphane. Ultimately though, his goal is simply to grow as much food as possible, and the fish do more to support healthy, hearty plant growth and a flourishing ecosystem than to serve as food themselves.
Local Roots has been experimenting with a wide variety of produce in their aquaponic systems, including tomatoes, basil, peppers, melons, cucumbers, eggplant, broccoli, chard, kale, peas, and more. It also grows koi, tilapia, catfish, and bluegill.
“Aquaponic systems mature over time,” Stéphane says. “They grow richer with a spectrum of macro and micronutrients. So if you think the tomatoes taste good this year, they’ll be even better next year.”
On the horizon, Stéphane is looking to start a venture that would establish a large aquaponic CSA program offering weekly boxes of fresh produce and fish. He’s presently looking for funding to make that goal, and a handful of other large-scale projects, a reality. For now, in addition to consulting and building aquaponics systems, he sells plant starts and produce at farmers’ markets and a limited amount of microgreens through direct-sale relationships.
“Every week is better than the last,” he says. “I am very optimistic about the future of aquaponics and its ability to help feed our growing population sustainably.”