Crewmember Report: Benicia, California, Spaceship Earth: Aquaponics!
By Constance Beutel
I RECALL A CONVERSATION FROM LAST YEAR about someone stopping by the Benicia Community Garden on First Street and asking whether Benicia had any organization or person doing “aquaponics.” Then, the other day, I was watching a program showing a large converted warehouse doing aquaponics that was actually profitable as a Community Supported Agriculture (CSA) business selling its organic vegetables and fish — rainbow trout and tilapia.
Trying out a hydroponic growing system for growing tomatoes many years ago, I became happy with the amount of fertilizer that needed to be added to the water. Aquaponics, I am learning, is a different kettle of fish altogether. This method of food production is also called pisciponics because it most often uses and raises fish as it replicates a natural system.
There is quite a bit written about aquaponics — it is an especially interesting farming method for not only semi-arid climates like ours in California but especially for locations where water is a scarce and precious resource. Estimates are that aquaponics uses 90 percent less water than standard agricultural watering, and of the water it does use, it conserves for reuse more than 97 percent. I even read an article about using this agricultural method at the research station in Antarctica, which makes sense since it’s very costly to ship fresh food there. And a website, Aquaponics and Earth, says that one micro-farm can sustain a family of four for life!
An abstract from Cal Polytechnic explains the process well: “Aquaponics . . . utilizes a combination of fish and plants to create a balanced system. In this arrangement fish waste (ammonia) is converted into nitrate by two types of bacteria in a series of chemical reactions. The plants then use the nitrate-rich water for growth while simultaneously “cleaning” the water for the fish and removing potentially harmful nitrogen buildup. Without each other’s contribution to the system, the system would fail.
“The grow bed is designed to be a filter for the fish and also a growing area for the plants. This type of filter is called a bio-filter, which has living bacteria that break down the ammonia. This process is called the nitrogen cycle.”
The abstract goes on to describe the basics in setting up a aquaponics system:
• Cycle timer
• Solar panels
• Aquaponics system
A search on Amazon.com found more than 300 books, kits and systems. I was amazed at what a credit card will buy in terms of aquaponic systems — everything one would need for the backyard, warehouse or greenhouse!
I just hadn’t realized how mature this industry is. One company, Bioponica, has systems from A to W — that is, aquaponics to worm farming!
Somehow, Benicia seems like a perfect fit to explore this kind of food production system!
Finally, one of the articles I read recently was from the Canadian Journal of Agriculture, “Optimization of Water Circulation Period for the Culture of Goldfish with Spinach in Aquaponic System.” Who knew that years ago my little goldfish, Slunce (Czech for “sun”) and I could have been reaping the spinach bounty of his dirty fishbowl? Now, at least, I do!
• Water and energy conservation grow system: Aquaponics and aeroponics with a cycle timer: http://digitalcommons.calpoly.edu/eesp/181/
Constance Beutel is a member of Benicia’s Community Sustainability Commission. She is a university professor and videographer and holds a doctorate from the University of San Francisco.