Over the past year and a half, Patrick Durkin has been converting a former Manorville commercial fish farm into an aquaponics operation where fish and plants grow together. Wait. Aqua who/what?

Aquaponics is part of the movement toward decentralized, niche-type farms, Durkin said, that allow goods to be “grown close to their market.” True, but it’s a bit more involved than that. Here’s how the website howstuffworks.com explains it under the home and garden section:

“Aquaponics is a system for farming fish and plants together in a mutually beneficial cycle. Fish produce wastes that turn into nitrates and ammonia. These aren’t good for the fish if they build up too much, but they’re great fertilizer for plants. As the plants suck up these nutrients, they purify the water, which benefits the fish. Many cultures have made use of this cycle to grow better crops and nurture the fish as an additional food source. Rice paddies in China and Thailand have used aquaponic techniques for years. . . . Modern aquaponics is slightly more high-tech, but it’s still an efficient and environmentally friendly way to produce food. Fish are kept in large tanks and the plants are grown hydroponically; that is, without soil.”

On the East End, fresh-picked watercress, mint and Vietnamese coriander are available at Fruit of Life Aquaponics, Durkin’s nascent operation, and rosemary is almost ready for harvesting.

Durkin, 30, of Manorville, said aquaponics is the urban farming of the future.

“It’s taken some getting used to, and the fish are just coming of age now, so we’re ready to think about growing the farm some more,” he said.

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Durkin, who still works full-time as the office manager for Green Forward Landscaping in Bayport, rents the building that houses the fish tanks and runs his business with the help of friends and family.

He uses passive solar to heat the water and maintain a 50-degree temperature. Well water fills the eight fish tanks, each of which holds 5,000 gallons. “I used heaters the first year, and tried to grow basil and tomatoes during the winter, and it was pretty expensive,” Durkin recalled. “It wasn’t working, so I switched to climate-appropriate greens and passive solar. Right now we’re just starting to break even.”

Durkin said he learned about aquaponics by watching YouTube videos and reading up on the subject, although his background as an aircraft mechanic with the New York Air National Guard and a worker on an organic farm near upstate Watertown has helped.

He grows butterhead lettuce for personal use, and can tailor what he grows to special requests. The mint and watercress, both tolerant of cold, are what he calls “cut and come” plants. “You cut them back to the crown and they’ll regrow, so they don’t need reseeding,” he said.

Along with one tank of goldfish and koi, which he raises to provide a stable environment for the system, he’s also raising rainbow trout that soon will be ready to sell.

Durkin retrofitted the fish farm for his aquaponics operation, adding wooden frames to suspend tiers of 4-inch PVC pipes that the plants grow out of. They’re fed via drip lines, and he uses a 3-horsepower, off-the-shelf pool pump to move water through the system. He has pipes over all eight tanks and along one wall of the greenhouse.

Durkin delivers watercress to Cavanaugh’s Restaurant and Pub in Blue Point, and he is ready to expand his business now that plants and fish are established. Todd Brunn, who teaches science at Montauk Public School, drove to Manorville to check out Durkin’s operation as part of his research on ways to use water from the school’s 500-gallon koi pond.

Brunn, 43, now has a science unit teaching students how to grow plants with water from the fishpond. Recently, he had first-graders plant seeds in a fibrous material that’s soaked with water pumped from the koi pond into three large containers, then drained back into the pond.

“We’ll turn the pump on and fill it, then drain it,” Brunn said of each of the containers. “Fill and drain, a constant cycle about every 20 minutes. The plants will use that nitrogen to grow.”

For more information or to schedule a tour of Durkin’s aquaponics farm, visit folaquaponics.org