Article by Sam Riches, Canada.com
Aquaponics has ancient roots.
The integrated system, where raising fish is combined with growing plants, was first used by the Aztecs and in rice paddy systems across parts of Asia.
Today, several of Canada’s licensed producers rely on aquaponics for their cannabis production. Tanner Stewart, co-founder and CEO at New Brunswick-based Stewart Farms, recently shed some light on his company’s aquaponic operation in a Q&A with Canna.ca.
Growing up “in the woods” in Miramichi, N.B., environmental sustainability became an early point of focus for Stewart, who now takes a similarly thoughtful approach to cannabis farming.
Cannabis grows demand significant amounts of water and energy, in addition to pesticides, fungicides and fertilizers. Aquaponics, by comparison, is energy-efficient and is touted as leading to accelerated growth and higher yields as the plants receive nutrients around the clock.
“Over the years, I never stopped learning about sustainability, so when it came to aquaponics, the marriage of land-based aquaculture and plant farming, I immediately got it. That was it for me. I realized that sustainable agriculture, and living ecosystems, is where I was supposed to be,” Stewart told Canna.ca.
His first foray into aquaponics was in 2018 and focused on lettuce and leafy greens, but with the lifting of cannabis prohibition, Stewart changed his approach. “I said to myself, ‘I’ve been smoking weed for 18 years… but only eating lettuce for five… ‘so I took my technology experience to that point, and turned my focus to Stewart Farms in January 2018. A vertical farming and aquaponics format. It just makes more sense to advance our tech with the most valuable fruiting crop in the world,” he said.
Stewart said another benefit of aquaponic cannabis is the flavour profile that can be created. “A cannabis plant in a living system really has that flavour profile that a lot of hydroponics growers can’t hit,” he explained.
“A living system will help create a robust terpene profile that microbes can create within the plant. By combining a fish farm with a cannabis grow, and focusing on genetics, our goal is to create flavour profiles so incredible, with terpenes so high, you can taste the blueberries in the blueberry kush,” Stewart added.
In 2018, Hamilton-based Green Relief became the first aquaponic medical cannabis facility in Canada. “Aquaponics is one of the more sustainable forms of growing, primarily because it decreases the amount of fresh water consumed, eliminates the need for additional added fertilizers and creates two cash crops, from one system,” Melanie Pearson, manager of aquaponics at Green Relief, previously told The GrowthOp.
But that doesn’t mean it’s easy.
It can be difficult to strike the balance between environmental conditions and the nutrient balance within the system. Still, with high yields and little waste, Stewart encourages those interested in starting a small-scale aquaponics grow to give it a try.
He suggested starting with Tilapia, as they have a more vegetarian-based diet, and to remain mindful of the salt content given to the fish.