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Live Green Symbiotic farming marries fish and vegetables

Aquaponic operation provides year-round greens

At the root of the organic local food movement is this: know your farmer, know your food. Living that maxim, however, is easier in some places than others. Thankfully, it is becoming easier in Powell River.

An increasing number of local farmers produce products for sale to residents. A wide variety of meats, seafood, honey, fruit and vegetables is simple to find. A larger issue for those living in a temperate rainforest climate zone is where to find locally grown fresh vegetables in January.

Answering that call is a partnership of two families who recently moved to Powell River.

Gayle and Jeff Kier along with Gayle’s sister Marcia and her husband Don Nahorney bought their home and farm 10 minutes south of town on Swede Bell Road a few years ago.

Since then the four semi-retirees, as they refer to themselves, have built a 7,300 square foot aquaponics greenhouse on the property with the aim of being more self-sufficient and supplying Powell River with vegetables year round. They have created Sunshine Coast Aquaponics.

“The commute is nice, about 150 feet,” said Jeff. “Haven’t had a traffic jam yet.”

He explained that when they created their business plan the partners decided to put their focus only on the Upper Sunshine Coast, confident they would find a market for year-round lettuce and other more conventional greenhouse vegetables. Their overall approach to growing, however, could not be more unconventional.

Aquaponics is a method of agriculture where fish and plants are cultivated together in an integrated system. It’s a symbiotic operation that does not allow for any chemical herbicides or pesticides.

At Sunshine Coast, about 400 Nile tilapia live in large tanks off to the side of the growing beds. Water is circulated from the tanks in a closed system to eight long, shallow grow-beds where styrofoam rafts float on top. The rafts have 36 holes sized for seed plugs. As the plant grows, its roots absorb the nutrient-rich water. Harvesting a head of lettuce is as simple as removing it from the raft and cutting out the core.

The water from the fish tanks is run through biomass separators and lava rock containing naturally occurring bacteria that feed on the ammonia in fish waste to create usable food for growing plants. Nitrifying bacteria, Nitrosomonas and Nitrobacter, are a commonly used species in aquaponics. These bacteria work together to oxidize the ammonia into nitrite and then nitrite to nitrate which is usable by plants as their main food supply. The plants in turn help clean the water which is cycled back into the fish tanks.

The system runs on about 28,000 gallons of water and is extremely water and energy efficient. Jeff explained that in one day the pumps use the power of four 100-watt light bulbs to circulate the water. More energy is required to run lights and fans, but he added they are looking at moving toward solar panels for their electricity and solar water heating. A limited amount of water has to be replaced to account for evaporation and the growth of the lettuce. They currently use biomass and wood heat to regulate a constant 20° celsius water temperature. He estimates that the greenhouse uses only 10 per cent of the amount of water farmers use to grow the same vegetables in soil.

It takes a little over a month to grow a head of lettuce and Jeff said he and his colleagues hope to bring greenhouse production up to 2,000 heads per week.

The idea of growing vegetables and fish together is not a new idea, said Jeff, estimating that backyard farmers have been tinkering with the idea for around 30 years. However, not many commercial operations grow produce for direct sale.

Jeff and Gayle were experimenting with the aquaponic process for a few years before moving to Powell River. “There’s no manual for this,” said Jeff. “Everyone has their own ideas, there’s no right or wrong. You have to just figure out what works for you.”