Aquaponics ecosystems turn fish waste into plant food for homegrown edibles

The hair-like white roots of a red leaf lettuce plant hang in the air between small nodules of red and gray lava rock.

Garret Rodgers had just yanked the plant out of the bin it was in. He harvested the bulk of the leaves on a recent Wednesday and placed the stalk and roots back in the bin, between several varieties of lettuce he’s allowing to go to seed.

There’s a lettuce jungle on one end of the 7-foot-long, 6-inch-deep bin that contains the plant portion of Rodgers’ aquaponics system. At the bin’s opposite end, a watermelon plant, cherry tomato plant, basil, parsley, and a bell pepper plant cozy up next to one another.

Adjacent to that is the piece of the system that makes it complete: a fish pond with 15 rainbow trout and around 50 crayfish.

click to enlarge Aquaponics ecosystems turn fish waste into plant food for homegrown edibles
PHOTO BY CAMILLIA LANHAM
WATER AND WASTE: Garret Rodgers reached into his fish pond to grab a crayfish, an edible animal which also creates the waste needed to grow the plants in his aquaponics system. The water flowing out of the white PVC pipe was cleaned of its waste by the plants.

All together, the food growing system Rodgers built in his mother’s Nipomo backyard is a complete ecosystem. Bacteria, animals, water, plants, sunlight, and waste—nutrients—work together. Without one piece of that ecosystem, the system would fall apart and its pieces would die.

It mimics the natural world.

It grows produce and protein, uses 90 percent less water than traditional farming and gardening methods, and Rodgers thinks it’s what farming will look like in 20 to 50 years.

“I hope it is, if politics doesn’t get in the way somehow,” he said. “The way we do it now isn’t working. I think aquaponics is going to be how we grow food in the future. Zero carbon emissions, zero waste, and zero impacts on the environment.”

He envisions community and individual aquaponics systems taking the place of swaths of mono-cultured crops. Eventually, he wants to teach people how to run their own systems, but for now, he’s just working on perfecting his own.

“It really is a hobby for me,” he said. “Every night I come home from work, and this is what I do.”

click to enlarge Aquaponics ecosystems turn fish waste into plant food for homegrown edibles
PHOTO BY CAMILLIA LANHAM

Water is pumped into the planter bin from the fish pond. That water contains fish waste. Microbes and bacteria turn that fish poop—ammonia—into a form of nitrogen that plants need to grow. The plants eating up that source of nutrients cleans the water, which is then gravity fed back into the fish pond.

Rodgers rakes his hand through duckweed—a layer of teeny, tiny green leaves on the top of sitting water at the lettuce-jungle end of the bin.

The year-old project is going to get a facelift; its ecosystem isn’t balanced right, so it’s time to try something new. The system is getting clogged, and Rodgers thinks he could grow things more efficiently with taller bins and bigger rocks, so he’s in the middle of rigging up different digs for his plants.

For Rodgers, aquaponics—and growing things—is a love worth pursuing until he gets it right. Biology is kind of his thing—he graduated from Wesleyan University with an undergraduate degree in biology and grows living organisms for Ward’s Science—but you don’t necessarily have to be a bio whiz to work an aquaponics system.

You just have to be into it, be able to troubleshoot, and to have the ability to maintain it.

Santa Barbara Aquaponics entrepreneur Kevin Childerley is way into it—he’s not a biologist, but a writer—and willing to work out the kinks. Childerley has been building and adjusting aquaponics systems on a friend’s 13-acre property in Santa Barbara for the past three years.

click to enlarge Aquaponics ecosystems turn fish waste into plant food for homegrown edibles
PHOTO BY CAMILLIA LANHAM
ROCKY ROOTS: Plants don’t necessarily need soil to grow, but they do need nutrients and water—both of which they can get from an aquaponics system.

At the moment, he’s rounding out the concept for two kinds of systems—one that produces fruits and vegetables as its major output and another that focuses on fish, or more particularly, catfish, because that’s what Childerley uses on the protein end of things.

He said the systems produce twice as fast as traditional farming methods do, and aquaponics provides an answer to the water dilemma.

“You really have to come see it to understand it,” Childerley said. “This thing really works.”

He has a thought-train similar to Rodgers and wants to teach people to build their own systems and give them the basic tools they need to do it, but he isn’t ready quite yet. He is, however, ready to spread the word, and leads tours through the systems he’s built. His next tour will be on Oct. 4.

The response Childerley gotten to the aquaponics concept has been overwhelmingly positive. People are interested.

“I think it gives people hope that they can grow their own food; it’s very empowering to grow your own food,” he said. “It tastes a sight better than what you can buy at the supermarket.”

Growing ecosystems

Visit the Santa Barbara Aquaponics website, santabarbaraaquaponics.com, to learn more about what Kevin Childerley is doing and about the tours he leads through his ecosystems.

Contact Staff Writer Camillia Lanham at [email protected].

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