Aquaponics involves the combination of hydroponic growing and aquaculture in a recirculating ecosystem with a symbiotic relationship. This particular type of aquaponics system is called a Media-Based system where plants are directly sown into clay pellets.
The system was built using an Intermediate Bulk Container (IBC tote). These are perfect containers to use for these systems (as long as they are food grade) because they, like tires, are ubiquitous to the planet with a long life span. They are also not very expensive, ranging from about $30 - $80. This fits perfectly into the ethos of Earthship Biotecture because it's one more way to repurpose garbage and put it into useful function.
When cut down to the appropriate size, the fish holding tank contains about 175 gallons of water with a growing bed of Hydroton (clay pellets) media on top. There are 21 fish in the tank, which are a unique species of Carp commonly found in New Mexico. Believe it or not, the Carp is the most widely consumed fish in the world (thanks Asia!), allowing this system to yield edible protein. The grow bed has a variety of plant starts in it such as tomatoes, basil, broccoli, peppers and parsley.
The system (diagram below) is built after the nitrogen cycle is established. Cycling is the first step before the addition of fish to establish a beneficial bacteria colony within your aquaponics system. The water is then tested for pH, nitrate, nitrite and ammonia levels. Water from a fish tank recirculates and is pumped through a grow bed by an aquatic pump. Fish waste (ammonia) provides the plants with nutrients, and plants filter the water to keep the fish healthy. The bacteria convert ammonia and nitrite to nitrate. Plants uptake nutrient rich water where it is filtered and clean water is then returned to the fish tank.
An interesting technique used in these systems involves a bell siphon, which creates a drain and flood cycle for the grow bed. This is a common piece that is unique to Media-Based aquaponics systems which sucks the water out of the grow bed and floods it back in through the ideas of basic physics. This is advantageous in eliminating the need for a timer and extending the life of the aquatic pump.
Aquaponics fits seamlessly into the mission of Earthship Biotecture. The idea of harvesting one’s own water and using the water in Earthship’s system four times over relates directly to the conservation of water in an aquaponics system. These systems use 90-99% less water than that of a soil-based garden. Therefore they are 9x more efficient in terms of water usage. Food production is another fundamental principle within Earthships. This system allows us to maximize growing space and introduce a protein source within the greenhouse space allowing for a better direction into food sovereignty. The nutrient density of the plants is high and flavorful, comparable to plants grown in rich soil. Aquaponics systems’ plants grow about 3x faster, allowing for the first crop harvest within 6 weeks of establishing the system. The fish tank in an aquaponics system also acts as an element of thermal mass, which we know is a principle of Earthship design. Water is denser and is 4x more efficient as thermal mass than masonry work or rock. Adding a body of water in the greenhouse also creates a more humid environment that is good for plant health and increases comfort levels particularly in arid environments. Aquaponics is also a more passive system which reduces the workload, removing the necessity to do any weeding and the elevated grow bed saves on bending, reducing back problems.
James Fry is an "Aquapon" by trade and has been building systems for over two years now. He started building hydroponics systems in his dorm rooms in college. The idea of using a small space in an urban environment sparked his interest and lead to the natural progression from hydroponics to aquaponics systems. James has interned with Green Acre Aquaponics in Brooksville, FL and serves as a committee member of the Aquaponics Association. When talking to James, he explained that he considers himself a Permaculturalist, an Aquapon and an Earthship Biotect (in that order) with the intention of tying each of these practices together.
James is currently working on building a commercial rooftop aquaponic farm in Boulder, Colorado. He also does aquaponics consulting for both corporate and individual projects. When asked about his goals, he explained that his mission is “to empower people to provide for themselves.” We look forward to evolving and encouraging the addition of these systems into our design.
Learn more about James' journey at his blog, www.GrowEverywhere.com
More information about the system diagram:
Green Acres Aquaponics: