I count myself one of the lucky people who don't dread going to work during the end-of-summer slump in August. This time of year, when I unlock the gate in the morning and roll up the sides of the greenhouse, I can see the tomatoes are finally ready, the marigolds are in full bloom and everything green is thriving in the extended daylight hours. And I get to spend all day surrounded by these happy plants - and fish, too.
I work at Oko Farms, New York City's largest - and only! - outdoor aquaponics farm. Aquaponics, for those who need a quick refresher, is a way of growing plants and aquatic animals (usually fish) in water together in a recirculating ecosystem. Basically, fish waste feeds the plants, and the plants clean the water for the fish.
It's easy to understand why urban aquaponics is only increasing in popularity. Since aquaponics growing happens in water, there's no need to worry about contaminated city soil. Systems can be built to fit any space, from the smallest backyard project to a full warehouse. Aquaponics also uses considerably less water than soil farming, or aquaculture or hydroponics alone.
In the year since I've started working at Oko Farms, the farm has undergone a renovation, and I've learned a lot about farming fish, prawns and more types of plants than I can count. While I can't impart to you the specific wisdom gained from building greenhouses or harvesting prawns in the city (you'll have to work on a farm yourself for that), here are six lessons I've learned from my first year as a New York City aquaponics farmer.
1. Don't Forget Your Bacteria
Aquaponics systems are not as simple as "plants cleaning the water for the fish." The biological process that converts fish waste to plant food in your aquaponics system is reliant on two forms of beneficial bacteria, Nitrosomonasand Nitrobacter. These are also the same bacteria that convert waste into plant nutrients in the soil. If your fish are sick and your plants aren't growing, it's probably because there's something wrong with the bacterial colony in your water. Conversely, if the fish are healthy and the plants are growing well, you know you have a robust bacteria population.
2. Good Filtration Is Key
Plants, fish and your beneficial bacteria all depend on oxygen to survive. If solid waste from your fish builds up beyond a certain point, it ends up clogging your system and killing your bacterial colony. As stated above, this is a problem. While most experts emphasize the importance of collecting and disposing of solid waste, this is something that a lot of aquaponics beginners overlook.
3. You're Going to Accidentally Kill Fish (and Plants!)
This is going to happen. It takes time and practice to recognize how to prevent, recognize and treat fish diseases. In aquaponics, most people starting out aren't aquaculture experts, and my boss, Yemi Amu, says that you aren't a farmer until you've killed at least 10,000 fish. Especially, if like most aquaponics farmers you do not use antibiotics at risk of killing your bacterial colony, there's a very small margin for error. This year at Oko Farms we stocked our fish tank with a few hundred bluegill from a pond. When fish change environments so drastically, this leaves them vulnerable to disease due to stress. We consider it a victory that we still have over half of our bluegill, four months later!
4. Less Is Often More, and Simpler Designs Are Often Better
More complicated designs are not always better, even though they look pretty. There's often a temptation to get the newest, flashiest technology, or in indoor growing to have as many vertical layers as possible, to "maximize space." The people who give in to this temptation have not necessarily designed their aquaponics systems for ease of use or practicality. The most efficient design is one that allows for efficient farming, and scissor lifts are not only inefficient, but dangerous. Who wants to be dealing with dead fish, plants that won't grow, and an aquaponics system that keeps falling apart, with custom parts that aren't easily replaced?
5. Produce Sales Might Not Be Enough
The truth is, the economies of scale don't work for most people right now in urban farming, at least when it comes to produce sales. At Oko Farms, even with maximizing our available space, produce only accounts for one aspect of our income. In New York City, many urban farms make value added products, or have events if they have enough space. Oko Farms also does consulting and education. It's expensive to have a farm and pay city rent, and because much of our country's fresh produce is heavily subsidized by the government, it is incredibly difficult for small urban farms to keep up in any meaningful way.
6. You Will Never Escape Emails
This one is self-explanatory. Just because you're now a farmer, you're also a business owner and a lot of your time will be spent sending emails!
The lessons I've learned in my first year at Oko Farms don't end here just because my list does. I need to get back to the gorgeous late August flowers and the fish. But don't worry. In farming, you keep learning at least until you've retired, so stay tuned next year for more lessons from Oko Farms.