Fish Food: Chicago's Appetite for Aquaponics

The February issue of Mindful Metropolis, a Chicago magazine about green living, is on newsstands, and it features an article I wrote about several organic aquaponics farms that are planned for the city.

Here's a excerpt:

In aquaponics, the plants are fertilized with nutrients and bacteria from fish water, and the plant roots filter the water so that it can be circulated back into the fish tanks, creating a symbiotic loop between fish and plants. Growing Power actually has several urban farms in Chicago that are managed by Allen’s daughter Erika, but none of them incorporate aquaponics technology. In fact, no commercial aquaponics operations exist in Chicago, because Chicago law doesn’t currently allow it, but several key players would like to see that change. 

“There’s nothing on the books in terms of the zoning as far as fish are concerned, but because they’re living beings they’re considered livestock,” says 46th Ward Alderman Helen Shiller. “Well, obviously we have to separate that.” 

Shiller hopes to convert the former Salvation Army building at the corner of Broadway and Sunnyside Avenue in Uptown into a multi-use building that would house aquaponics fish tanks and grow beds, an educational center, a community kitchen, and an on-site market. But she needs to address zoning issues in order for that to become a reality. 

Allen caught a break with the Growing Power property, because it was already zoned for agricultural use when he bought it. “He’s the last farmer in Milwaukee,” Shiller says. “You could probably not do what he’s doing anywhere else in a city without having the same problems that we’re having.” Shiller recently raised the aquaponics issue with the Chicago Departments of Zoning and Community Development, and she hopes to see the livestock designation change within the next year. “More and more of our colleagues are saying, ‘We really want to do that, so as soon as you figure it out we’re going to do it,’” she says.

Read the whole story at Mindful Metropolis, where you can read a digital version of the entire magazine.

-Mark

Farming With Fish at Growing Power

On Tuesday I wrote about the composting operation at Growing Power; today I'd like to focus on the aquaponics technology - the combination of aquaculture and hydroponics - used at the farm. We've covered aquaponics on this site before, when Dorothee and I went down to Flanagan, IL and made a video about an aquaponic farm called AquaRanch. At Growing Power they do some things similarly to what we saw at AquaRanch, but most of they're setup is very different.

At AquaRanch, Myles Harston keeps the fish in large, circular tanks that are located in a separate room from the vegetable grow beds, and he runs the waste water from the fish tanks to the grow beds. At Growing Power, space is utilized more efficiently. The fish at Growing Power are kept in long, 4-foot deep rectangular tanks that have been dug into the ground. One benefit of this design is that the ground helps to insulate the fish tanks, and it leaves more vertical space to build grow beds (and the Growing Power folks use every square inch of that extra space).

When I visited, we actually saw some workers building a new aquaponics bed (above, at left). My tour guide told us that the materials needed to construct one of the beds only costs about $4,000, with the fish tank liner accounting for most of the cost.

Above the fish tanks, the Growing Power folks have rigged a two-tiered shelf system that serves as grow beds. The water from the fish tanks, which is loaded with fish waste that's rich in nutrients and microbes, is pumped up to the elevated grow beds. The grow beds are set at a slight angle, so the water flows slowly from one end to the other. One of the most common plants grown in these type of bed is watercress (pictured at top), because it likes a lot of water and it does a good job of filtering and cleaning the fish water.

At Growing Power they use both tilapia and yellow perch in the aquaponics systems. Yellow perch are native to the Great Lakes, so they can handle cold water, but tilapia are tropical fish, so their tanks must be heated. Unlike AquaRanch, where the fish are harvested and filleted on-site, Growing Power only sells whole fish at present, but at $6 per pound it's a bargain compared to AquaRanch's $15 per pound tilapia fillets.

-Mark

Composting at Growing Power

It doesn't have much sex appeal, but composting is one of the most important techniques used at Growing Power's 2.5-acre urban farm in Milwaukee, as well as the 30-acre facility in the nearby suburb of Merton. Throughout the two-hour tour I took at Growing Power on Saturday, composting was a constant point of emphasis. It's the reason that Will Allen and his staff have a never-ending supply of nutrient-rich soil and fertilizer, and through composting they're able to divert thousands of pounds from landfills every year.

In the beginning of the tour we came upon a greenhouse where a group of volunteers were just finishing filtering worms out of a wheelbarrow full of soil (below, at left). I've got a worm bin under my kitchen counter, so I'm used to handling worms, but I was still sort of shocked to see the wriggling mass that looked like ground beef in the bottom of the wheelbarrow (below, center). A few minutes later, we bumped into Will Allen, who was busy spreading the worms throughout a big bin of compost (below, at right).

Composting at Growing Power isn't confined to the worm bins that line the insides of the greenhouse. Large heaps of compost can be found in between the greenhouses and in the small clearing near the livestock at the back of the property. Growing Power collects whole shipments of food waste directly from wholesalers, used coffee grounds from local roasters, beer mash from Lakefront Brewery, and newspapers from the Milwaukee Journal Sentinel.

The most innovative use of compost we were shown at Growing Power was as a source of heat for a small hoop house (below, at left). Compost is heaped in the corners of the greenhouse, and the heat generated by the soil bacteria in unfinished compost is captured and used as a furnace to heat the greenhouse throughout the winter. According to our guide, the center of those compost heaps can reach temperatures of 160 degrees.

-Mark

Taking a Tour of Growing Power in Milwaukee

Over the years, we've read and heard a lot about Growing Power, a large urban farm on the northwest side of Milwaukee, but until this weekend I had never been there. So on a trip to Milwaukee, I set aside a couple of hours and took a tour of the farm (tours are given every day, and they cost $10). Growing Power was started by Will Allen, a former pro basketball player who grew up on a farm. Allen bought the property in the early 1990s, and it has since grown into a Milwaukee institution that attracts hoards of visitors and volunteers and produces loads of organic vegetables.

The thing that struck me most about Growing Power is the sheer amount of food production that takes place on the less than three-acre plot. Aquaponic grow beds that are rigged up with two-by-fours are layered, with the top beds capturing the UV rays from the sun and grow lights hanging over the lower levels. Beneath them, fish are grown and harvested, and hanging baskets hang from the sides, growing more vegetables. No space is wasted, inside the greenhouses or out.

Will Allen didn't guide the tour, but he had a brief cameo, swooping in to spread a few handfuls of worms in one of the big compost bins in the middle of the greenhouse.

The rub on Growing Power is that it isn't a business model that could easily be replicated elsewhere, because they depend heavily on various grants (Allen recently was awarded a MacArthur "genius" grant) and volunteers. Additionally, Milwaukee allows Growing Power to keep fish and livestock on-site, because agricultural zoning was grandfathered in when Allen acquired the site.

That all may be true, but Allen and Growing Power still set a good example of the potential that unused urban spaces hold, and Growing Power is currently doing outreach, helping people in other cities, like Buffalo, Louisville, and Detroit, to set up similar urban farms. In fact, my tour group included a few guys from Reno to study some of the techniques used at Growing Power in hopes of replicating it back home.

In the course of the week, I'll post some more photos and take a closer look at some of the techniques used at Growing Power. For more about Growing Power, check out this recent New York Times Magazine article about Will Allen.

-Mark