FoodChain's Becca Self (right) chose the healthiest seedlings for students to add to their sustainable food-production system. (Photos from FCPS)
By Tammy Lane
Fayette County Public Schools
Marine science students at Tates Creek High School are raising largemouth bass and growing vegetables without soil in a new three-level aquaponics station, which recycles water in a sustainable food-production model.
In the simple setup, water from the fish barrel trickles into the grow beds, which routinely drain so the roots get some air and the plants aren’t overly saturated. The water then is pumped back into the barrel of bass.
“Throughout generations, it’s been done. It’s the whole idea of being sustainable and increasing your output with low input,” said teacher Diana Mullins. “In this closed system, the plants are taking less time to grow so you’ve got a faster turnaround. In six months, the fish will be about plate-size.”
The project is a collaboration with FoodChain, a local nonprofit run by Becca Self.
“The great thing is the fish and the plants have a symbiotic relationship. The fish waste is used by the plants as food, and they filter the water so it’s clean to go back to the fish,” she explained. “It uses less than 10 percent of the water that conventional agriculture uses, so it’s a really environmentally friendly way of producing food.”
The Tates Creek project is home to about 15 largemouth bass that came from Kentucky State's aquaculture center.
The effort began with students building the wooden frame, which sits on cinderblocks in a corner of their science lab. They also cut and prepared the three plastic barrels that now house more than a dozen bass, assorted vegetables planted amid small chunks of expanded shale, and a fountain pump.
“It’s a replica of the prototype we have in our facility,” said Self, who previously worked at Seedleaf and has assisted the school’s Generation Green club with other projects. “It’s doable by anybody who takes an interest in it.”
The 55-gallon blue barrels are repurposed, the shale came from a local landscaping company, and the PVC pipe, shop lighting and other materials were easy to find and affordable. In the next month or so, FoodChain will start on a larger, almost commercial-scale model for demonstration purposes. Meanwhile, the Tates Creek students will continue to collect data and maintain their system for the rest of the school year.
“It’s fun and it’s useful,” said junior Jordan Phillips, who helped adjust the lighting in a recent class.
Mullins’ two groups monitor the system’s water quality throughout the carbon and nitrogen cycle as naturally occurring bacteria convert ammonia from the fish waste into nitrite and then nitrate, which nourishes the plants.
“We’re looking at the pH level to make sure the water is healthy for the fish,” Jordan explained as classmates checked samples.
“It’s all about having a stable ecosystem and ways to get food without using up limited resources,” added junior Helena Jackson, who dropped in a few more food pellets for the bass, which came from Kentucky State’s aquaculture center.
Though local greenhouses had few seedlings this month, Self did bring in a small tray of kale and other greens along with seed packets of lettuce, collards, tomatoes, cucumbers and hot peppers. Some students sprinkled tiny seeds directly into the grow bed to see if they will sprout, while others gently settled the seedlings in rows among the shale. They also put some seeds in a starter tray for later transplants.
Self, former classroom science teacher, will return periodically to check on the progress.
“Several times throughout the school year, we’ll harvest the plants, enjoy salads together and likely try some new foods together. And then, near the end of the year, the fish will be large enough for harvest. Our plan is to have a meal together celebrating the success of the system and collecting recommendations for how to improve things for the next cycle,” she said, adding, “We fully expect that these students will naturally rise up to become teachers and mentors to the next year’s participants.”