The smog of Beijing

Beijing, 14 September, in a hutong near Beixinqiao metro station: 167 μg/m3. In Switzerland the motorway would be shut down at this level of pollution – but for Beijing, the air is good. In winter, the concentration of fine particles often reaches 400 μg/m3. China’s growth is a blessing, but the cost is high.

Michael Eddy and I climb onto the roof of an old one-storey brick building. He has installed his aquaponic unit there. It consists of a tank with some sort of green plants growing on top of it tucked away under a geodesic dome made of triangular supports. After a few years in China, the Canadian artist decided to treat himself to this system. 

In Shanghai, when I first heard about the growing number of tanks blubbering away on multi-storey residential buildings in China, and how private individuals were raising clean and healthy foods in them – such as lettuce and fish –, I thought it was just a rumour. I have no statistics, but Kai Kottenstede, a young German who has been studying China’s food crisis for years, told me later that aquaponic units are most likely only for the select few who have enough time and money.

It is in Beijing that I unexpectedly come across what I have been looking for. 

Peppermint is growing on top of Eddy’s aquaponic unit, and some spinach and tomatoes. Below them, in the bathtub-sized tank, a few medium-sized carp are swimming around.

“It’s an ecological cycle,” says Eddy. “We just have to feed the fish. Their excretions fertilize the lettuce, which then purifies the water.” But it was hard work to get the system going and find the right balance. So far they have mainly harvested peppermint. According to Eddy, the spinach and tomatoes are not doing so well. They have also eaten two fish so far. 
 
This is not much when you consider that a group of almost ten architects, artists and paper tigers worked for several months to install the system, under the sceptical gaze of their hutong neighbours.

“China should actually be the ideal country for solutions like these, “Eddy says. There are plenty of good reasons to install such units – for example, they conserve more water than planting in the earth does. And for a farm, they are relatively space saving. He rubs the back of his neck. “For us, it was basically an experiment. We began working on it in 2013. The point was to learn to understand a topic like equilibrium together.” 

Kai Kottenstede says the small water-tank movement is a reflection of something bigger: “Aquaponic systems are essentially about giving consumers total control of the production chain. In China, enterprises that take food safety seriously are taking the same route. They are incorporating every step of production, from the farm to delivery.”

Complete autarchy is the logical consequence and a way to opt out of a food system that provides people with little that is healthy. 

Eddy’s Japanese wife, Emi Uemura, is holding the baby. They want to move soon – to Canada, where they will be able to concentrate on their work and not have to check what they eat all the time. In Beijing, Uemura can only go out with their child when the air is not too polluted. Otherwise she has to stay home. People who can afford it have water and air filters in their flats – and perhaps an aquaponic unit as well.

First modelled on computer, the bio-dome’s structural integrity is tested by the reality of working with makeshift materials such as PVC pipes and bamboo. Located on the roof of HomeShop, we were never entirely sure whether the weight of the container would be too much for the building. © Michael Eddy

The container housing the aquaponic water-cycling system is made from rudimentary materials. Various growing situations were tested, including floating on foam, ebb-and-flood (where water flushes out when it reaches a certain level) and constant drip through an expanded clay substrate. © Michael Eddy

An early stage in a cucumber’s life. Getting the correct chemical balance for both the plants and the fish is not as simple as one might think. In theory: fish waste is carried by water pumped to the growing containers, and filters through the roots and substrate, which clarifies the water as the waste is broken down by microorganisms. © Michael Eddy
 

Several generations of fish were purchased at local fish markets and released into the aquaponic system. Catfish are true survivors, but with all of the variables involved in making an ideal ecosystem, not all of them made it through alive (though a principal reason may be the sorry state of Beijing fish markets). They were fed various grains, vegetation, bugs and pet food. © Michael Eddy