Aquaponic system combines lettuce, fish
By CRAIG REED
For the Capital Press
MYRTLE CREEK, Ore. — Fish and lettuce share the same circulating water in an aquaponics system recently developed by Jim and Jami Brown.
The result is a commercial venture. About 1,800 heads of certified organic mini-green and mini-red romaine lettuce are harvested weekly and sold at a couple farmers’ markets, Sherm’s Thunderbird Market in Roseburg and to Seven Feathers Casino Resort in Canyonville.
“We like growing something that is sustainable and self-reliant,” said Jami Brown.
While the Browns are new to aquaponics, they are the 22-year owners of Flyboy Naturals, a business that specializes in growing flowers and then freeze-drying the petals for sale. They had the space on their 11-acre property to diversify and were intrigued by the aquaponics process and philosophy.
“With drought conditions, it seemed like a neat idea,” Jim Brown said. “We’d heard of other people starting projects like this because of the drought, especially down in California. Our system uses only 5 percent of the water a normal ground crop of lettuce would use.”
The Browns have two 3,200-gallon tanks with about 500 tilapia fish in each. The water circulates the fish excretions, which are high in ammonia, through two settling tanks, where the solids settle to the bottom. The remaining effluent flows into troughs, where bacteria break it down into nitrates and then into nitrites.
Floating in the troughs are large perforated pieces of plastic with romaine lettuce heads growing up from 2-inch pots in each hole. The roots hang into the water and provide a home for micro-organisms to flourish, feeding on the nitrites and cleaning the water before it is pumped back into the fish tanks to begin the cycle again.
It takes about six weeks during warmer weather and eight weeks during cooler months to turn a lettuce seed planted in chopped-up coconut fiber in a small pot to a mature head of lettuce.
It’s considered living lettuce because it’s sold with the root system attached to the head and the roots enclosed in a bag with water. The moisture keeps the lettuce fresh for up to about three weeks.
The couple described the process as a closed loop aquaponic growing system, with the engine for the entire 26,000-gallon system being the fish.
The couple experimented with about 15 types of lettuce before deciding on the mini-green and mini-red romaine.
“They’re nice compact little heads of lettuce that make nice individual salads,” Jami Brown said. “They grow well in the system, and grow quickly.”
Initially, the Browns’ lettuce growing system was not certified organic, but they found their product couldn’t compete with other conventionally grown lettuce. They applied for and received U.S. Department of Agriculture organic certification from Oregon Tilth. The lettuce has much less competition in the organic marketplace.
Another benefit for the Browns that the aquaponic system provides is the liquefied solids that are sucked from the bottom of the settling tanks and then sprayed on the base of the roses grown for Flyboy Naturals dried petal business. Jim Brown called it “a better fertilizer than what we had been using.”
The system was constructed with expansion in mind. The couple is planning to also grow tomatoes and cucumbers in the aquaponic system, beginning in 2015.