Earlier this week, I posted a story about a net-zero greenhouse that grows food, fish and renewable energy – all in a small backyard space.
The greenhouse, invented by German physicist Franz Schreier, adds solar power to the super- efficient plant- and fish-growing system called aquaponics.
And while his invention is quite advanced, the basics of aquaponics isn’t. Aquaponics combines aquaculture and hydroponic techniques to create way of growing large quantities of organic food year-round in small urban spaces – without soil and with 90 percent less water than conventional growing. (Here’s a helpful explanatory video.)
How much food are we talking? Will Allen of Growing Power in Milwaukee, Wisc., has turned heads by using aquaponics to produce 1 million pounds of food a year on a mere 3 acres as cars whiz by on city streets and frigid Midwest winter temperatures drop to below zero.
Ann Forthoefel, a former director of the Portland Farmers Market, said Allen’s success in Wisconsin means Portland’s urban farmers could easily be using aquaponics to produce more local food. She’s been promoting the idea to city officials as a way to make Portland’s ecodistricts self-sufficient in food production.
“My goal is to make aquaponics part of our new vocabulary,” she said. “A lot of the ecodistricts own’t have land available. With aquaponics, you can grow in a warehouse. You can grow vertically.”
The basic genius of aquaponics is tapping the natural synergy between fish, water and plants. Fish excrete ammonia, and naturally occurring bacteria turn that ammonia into nitrites and nitrates that fertilize plants.
Aquaponics create a contained growing system that circulates “dirty” fish water into a clay and/or rock-lined planting bed. The plants clean the water and gather nutrients for growth before the water is circulated back into the fish tank.
It’s not a system you can start up overnight, said James Ragsdale of North Portland Farm.
His farm has spent a year and a half building an aquaponics system that will grow herbs and tilapia in a 10-square-foot insulated room outside. And the system isn’t up and running yet.
“It’s not something you can just put in in a weekend and expect to run as a turnkey system,” he said. “You can’t just put water in it and expect it to be running. People are obviously getting interested in it, but it really takes a lot of energy and resources to get it started.”
His farm was built on abandoned and contaminated land – not exactly prime growing turf. One of the benefits of aquaponics is it allows for farming in marginal urban spaces such as abandoned warehouses, Superfund sites or just the extra bits of space in and around people’s homes.
“People are obviously getting interested in it, but it really takes a lot of energy and resources to get it started.” —James Ragsdale, North Portland FarmBut Ragsdale said one of the main reasons he’s gotten into aquaponics is for the promise of protein.
“Fish just sound really cool,” he said. “We just kind of got excited about it. It seemed like a fun machine to build. We’re always looking at ways we can create our own protein source.”
Ragsdale said he’s found out the hard way – through lots of homework and fund-raising – that aquaponics isn’t easily accessible to everyone.
Demystifying the process
Jason Garvey, owner of the rainwater harvesting company Portland Purple Water in Beaverton, is out to change that.
Portland Purple Water sells rainwater harvesting equipment and specializes in water conservation. Garvey said he likes the fact that aquaponics is more water efficient than growing plants in soil. And doesn’t require herbicides or pesticides.
“It’s not the same as growing in mother earth in 1830, but it’s probably much better than growing in mother earth in 2012.” — Jason Garvey, Portland Purple WaterThe energy required to keep the water pumps and growing lights going is nothing compared with the energy inputs for traditional food production and transportation, he said.
“We’re trying to push as many people as possible to use it because the best environmental act any person can do right now is to grow their own food in their backyard, Garvey said. “The resources involved in the food production process otherwise are so exhaustive and so significant.”
His company is working to “demystify” the process “so people don’t need a PhD or an aquaculture background” to set up their own systems.
In the back rooms of his storefront in Beaverton, Garvey is growing tomatoes, cucumber, basil, radishes, carrots and lettuce to demonstrate how various systems can work. He said most systems cost $400 to $1,200 to get started.
For examples of just how far Aquaponics UK is taking their systems, check out this TED talk by aquaponics enthusiast Charlie Price: