At the entrance to a greenhouse at Bearhole Farms near Roxana sits a blue tank about the size of a small hot tub. Orange-finned flashes flit around the bottom and a pump emits a constant thrum.
“That's the engine,” says Bear Hole proprietor Cindy Stevens. The heart of the engine, which produces a perpetual harvest of 3,000 lettuce plants inside the 1,700-square-foot greenhouse, is fish. About 350 koi, common goldfish and channel catfish, to be precise.
In addition to swimming around the tank, the fish eat... and then when that food turns to fish waste, it is released into a system of channels that run under the lettuce plants, watering and feeding the plants. It's the perfect symbiotic relationship.
“You can't under-water or over-water and you can't over-fertilize or under-fertilize,” said C.J. Mears, who is partnering with Stevens in the Bearhole aquaponics operation.
“We are farmers in every sense of the word, but we don't need a tractor,” Mears said. “In fact, we don't even need dirt.” Even though the lettuce is grown in nothing but water fertilized with fish waste, it uses one-tenth of the water used in soil-based gardening, and even less water than a hydroponics operation.
Instead of soil, the lettuce plants float on foam mats. No pesticides or chemicals are used to grow the lettuce. As the water becomes enriched with “fish poo” it is processed through a moving bed “bioreactor.” Solids are removed from the water by “swirling the nitrogen” out, Mears said. “It is like a fast moving composting system,” he explained.
Then water, rich with the remaining nutrients from the fish waste, is transferred to the plants. The plants also serve as a natural filter, preparing the water to return to the fish tanks, where the cycle begins all over again.
Even the fish themselves cycle out of the farm operation — once they reach a certain size, they are sold and replaced with smaller fish. Stevens and Mears are also in the process of having the sludge certified as organic fertilizer, which would allow them to sell it for use on farm crops. Stevens already uses it on plants in her garden center.
“It's just another by-product of the system,” Mears said.
Still in its first year, Bearhole Farms has already found a steady market for its lettuce in local restaurants, Stevens said. A challenge initially was trying to assess the market, as far as which varieties would turn out to be the most popular. For a time, she said, Bear Hole Farms' Swiss chard was so popular she considered only selling that variety.
Ultimately, she decided to grow a variety of lettuces, from Swiss chard to romaine, as well as a mix of complementary greens that grow in the beds together, similar to a wildflower seed mix in a garden.
Stevens said she is hoping to try “micro-greens” soon — which are seedlings of a variety of greens and vegetables. Since lettuces and greens are cool weather crops, they are a natural extension of Stevens' warm weather business, Natural Creations landscaping. Having also run restaurants, Stevens said producing lettuce for area eateries seems like a natural progression for her. “I feel like I'm going back home,” working with restaurants, she said. “It's like a full circle.”
Mears, on the other hand, comes to aquaponics from a more technical background, having retired as a food safety professional, specializing in food-borne pathogens.
The two have been friends for years, and were introduced to aquaponics by mutual friends who own a large facility in Hilliard, Fla. “We were both amazed,” the first time they visited their friend's Traders Hill Farms, Stevens said. They were sold not only on the process, but also on the quality of lettuce produced. Not only does it taste better than conventionally grown lettuce, the two say, but it also has a shelf life of four weeks if stored properly. “It's unbelievable,” Stevens said. “The restaurants that use our product are very pleased with it.”
Mears said he feels their business has great potential for growth, as the farm-to-table movement begins to take hold in the area, as it has in other regions across the country. “We're hoping we're in the right position,” he said.
With advice from their friend Angela TenBroeck at Trader Hill Farms, Stevens and Mears built their own system — on a much smaller scale than Trader Hill Farms, but using the same principles. The gravity-based system is quite simple, consisting of two pumps: one water pump and one air pump.
For animal-lover Stevens, one of the most stressful parts of setting it up was getting the huge fish tank just right. At first, she said, her catfish were dying at an alarming rate, but she resolved that and “in the last four or five months, we've only lost one goldfish.” The water in the tank is tested three times a week for pH, ammonia, nitrites and nitrates to ensure the health of the “engine.”
Through the winter months, the Bearhole greenhouse continues to produce lush heads of bright green lettuce. With a seed-to-harvest time of 45 days, the little greenhouse produces 12,000 heads of lettuce in a year, cycling through the growing process four times.
Soon, Stevens and Mears will begin offering their lettuce to retail customers, with a monthly market day at the farm. The markets will begin Saturday, Jan. 7 and the two hope to continue them on the first Saturday of each month from 9 a.m. to noon. In addition to their lettuces and greens, they hope to offer fresh local eggs and local honey, adding other items seasonally.
The farm is located at 37765 Bearhole Road, Selbyville. For more information on the lettuce farm or the market, call Cindy Stevens at Natural Creations, 302-436-4856 or 302-542-1885.