Forget Chicken Coops—Fish Ponds Could Be the Future of Urban Farming
In a 950-square-foot second-floor walk-up in Manhattan, Jonathan Kadish grows rainbow chard, bok choy, and lettuce in a four-foot-square nook near his desk. It’s a two-story system: A soilless bed sits atop a fish tank in which two $3 pet-store goldfish swim. Kadish’s tiny garden is intended as a supplemental food source only, but it’s a small, urban-scale model of sustainable agriculture that has a growing number of people excited. “I get people from all over the world who ask to come visit and check it out,” he says.
Aquaponics, the marriage of aquaculture and hydroponics, is attracting a growing legion of fans for what is, given the right circumstances, an elegant, circular system: Fish waste provides a food source for edible plants, while the plants naturally filter the water in which the fish live. Aquaponics requires less space than what Kadish laughingly calls “terrestrial gardens” and uses one-tenth of the water. And while his apartment rig is powered by two goldfish, bigger operations produce fish (commonly tilapia) to eat in addition to vegetables.
One of the country’s leading purveyors of aquaponics supplies, The Aquaponic Source, recently reported a 20 percent growth in year-over-year sales. Meg Stout, chair of The Aquaponics Association, says that figure is “absolutely” in step with growing interest in aquaponics across the country. “One of my colleagues pointed out an article about the top 10 agriculture jobs that didn’t exist [25 years ago]. The number one job on the list was aquaponics farmer,” she says.
While Kadish calls his aquaponic interest a “hobby with benefits,” he has also helped build systems for schools and for a low-income housing development. He thinks aquaponics is a superb teaching tool, especially for children.
“It’s got everything you could want to teach about nature,” he says. “If you take a microscope and look at an aquaponics system, you’ll see all kinds of life in there, all living off each other. You’re only putting in the food, the light, and water, and what you get out of that is plants and stuff to eat. It’s pretty amazing to see fish food turn into tomatoes. That happens everywhere on our earth, that biological process of transformation.”
But with edible schoolyards, rooftop beehives, and backyard chicken coops popping up everywhere, why isn’t Portlandia making aquaponics jokes yet?
Stout says it’s just early days. “We haven’t gotten to the point where the academics, industry folks, and farmers have all come together” to make it take off in a major way, she explains. For a physicist and engineer like Stout, the science involved in building and running an aquaponics system isn’t outside her comfort zone, but that isn’t true for every beginning gardener. “The tech hasn’t matured to the point where you have somebody going to Walmart or Home Depot or Lowe’s with a little kit that will work every single time,” she says.
The team behind the popular Back to the Roots mushroom growing kits did release a slick, Dwell-approved mini-home aquaponics system, the AquaFarm, after raising nearly two-and-a-half times their fund-raising goal on Kickstarter in 2012. It’s design-y and cool and costs $60, as opposed to the $500 Kadish spent on his home system. To a beginner’s eye it looks great—but to a pro? Not so much.
“It’s a terrible design,” Stout says. “You’ve got this super nitrite- and nitrate-rich water and a design that lets in tons of light. You put light together with nutrients and you get algae.” Not good, especially for a fish tank that bills itself as “self cleaning.”
Both Stout and Kadish mention another reason why aquaponics hasn’t flourished, and it’s the kind of thing that has scared plenty of DIY-ers away from home canning and infused olive oils: Food safety. While there have been no reported cases of foodborne illness from aquaponics, “saying ‘I think it works’ doesn’t fly with the food safety folks,” Stout says.
“There’s a strain of bacteria that can live in an aquaponics setting that can be toxic to people, but it’s extremely rare. It would be like going to a Brooklyn bowling alley and getting Ebola,” Kadish quips. The Aquaponics Association has spent the last year drafting best practices, which will address food safety issues.
Here’s who might be interested in aquaponics: people who live in warm, water-scarce areas (there’s a lot of interest in Australia, Stout reports); anyone is interested in greater control over the source and production of their food; and those concerned about the environmental effects of climate change and current aquaculture practices that are polluting to aquatic systems. But for the moment, some of its biggest fans are a bit on the fringe: Think “the permaculture guys” and doomsday preppers, Stout says. In other words, aquaponics hasn’t hit the farmsteading hipster set just yet.
But just wait. Three bearded guys in Brooklyn are already on the case.