There’s a new phenomenon in local food: for the first time, select farmers are bringing fresh, home-grown lettuce and other produce not traditionally grown this season to winter farmers markets.
It’s all thanks to aquaponics, a type of growing that combines two well-known food production methods: aquaculture and hydroponics. Hydroponics grows vegetables in water but uses chemical solutions to give plants nutrients. Aquaculture is farming aquatic organisms — in this case, fish. The system relies on a nitrogen cycle, supported by nitrifying bacteria.
The response at farmers markets has been incredible, said Ross Williams, owner of Victory Farm in Derry. Each time he sets up shop at the Derry Farmers Market or the Salem Farmers Market he sells out of the lettuce, swiss chard, kale and arugula he produces. That’s because local lettuce is virtually impossible to find this time of year, and the stuff in the supermarket has rolled in from California, Arizona, and even South America, so it isn’t as fresh, he said.
Williams’ son Gavin Williams turned him on to the idea of aquaponic farming. Gavin, then an engineering student, was researching a better way to keep his goldfishes’ tank clean. Gavin added a second tank that would support plants and help clean the water. The duo then built a larger aquaponics system in Williams’ basement and ran that for several years, producing vegetables with the aid of tilapia. The endeavor grew to commercial proportions after they decided to purchase property in Londonderry. At the time, no New Hampshire commercial farmers were selling vegetables produced on an aquaponic system. By the end of 2013, Williams and Gavin started attending farmers markets.
The system grows both plants and fish. Williams uses tilapia. It’s a more efficient way to farm fish on a small scale, he said.
“There are large fish farms around, but most of those use a lot of water because they feed fish in ponds and flush out the tanks,” he said. “With aquaponics we use about 10 percent of the water that’s used in a normal market garden because we are recycling the water.”
Williams is still at about only a third of the production levels he expects to reach. He uses a deep water culture, the roots of his plants growing on floating beds in a foot of 70-degree water that keeps the plants alive through winter.
“One of the biggest killers of plants is overwatering,” he said. “We don’t have that problem because we make sure we have enough oxygen in the water. It’s actually the lack of oxygen that kills them.”
Aquaponics is ideal for small-scale farmers, Williams said, so while there are only a few commercial aquaponics ventures, it’s fast becoming a popular growing method for backyard enthusiasts.
Anthony Eugenio, the CEO of Green Harvest Hydroponics in Plaistow, says aquaponics is catching on in the state “because we have a good amount of farmland up here. It’s a nice way to have a full-revolution system. Indoor gardening is going through the roof because you’re able to get four cycles of production a year instead of one.”
That’s because outdoor growers rely on the sun for crop rotation, whereas inside life cycles can be manufactured using lights so the life cycle is much quicker.
But it’s not all fun and games. A lot can go wrong, both Williams and Eugenio said. Challenges can include dialing in the amount of fish per plant and determining what to feed the fish and what kind of plants; it takes time, because every environment is unique. On top of that, maintaining the right pH levels in the water is critical
“My setup might work fine with 10 tilapia to 10 square feet of plants, but yours might be different,” Eugenio said.
Though aquaponics is growing in popularity, it still isn’t as popular as ebb-and-flow hydroponics, Eugenio said, because for that system growers can infuse nutrients like phosphorous, zinc and potassium, which can mean faster, larger production. But ebb-and-flow doesn’t give growers the ability to eat the fertilizer, which in aquaponics is the fish.
“Aquaponics is less wasteful,” Eugenio said. “You can breed the fish and eat the fish. It’s a cooler way to go and it’s a nice way to go. … Most of my big aquaponics growers use tilapia and that is for cultivation of fish as well, but I do also help them set up for more feng shui as well, where it just looks nice.”
As seen in the February 6, 2014 issue of the Hippo.