Cannabis Aquaponics: From Fish to Fertilizer

In one of the two 150-gallon tanks are some of the 50 tilapia. For the past two years, Strathcona Christian Academy Secondary students in grades 10 through 12 have been busy tending an aquaponics farm. The system was designed and developed by students, and it breaks down the by-products from fish to produce nitrates and nitrites. These are then used to fertilize the growing vegetables, which also clean the system’s water to recirculate into the fish tanks on January 16, 2017. Photo by Shaughn Butts Janet French Story

By: David Wilson |

From the first shaken fists to the approval of C-45, proponents of legal cannabis have been leaning on the “all natural” clause for as long as legislators have been shaking their heads.

When it comes to harmony with nature, consumers need look no further than one perfectly synchronized, fish-fueled cannabis farm. “We’re letting nature do the work,” says Steven LeBlanc, co-founder, and president of Hamilton-based Green Relief. “We’ve created a perfectly balanced ecosystem.”

LeBlanc is talking about the company’s aquaponic farming method, a system by which fish supply nutrients to the plants through a continuous cycle of energy and waste production—what he describes as a “closed loop”.

It’s the first medical marijuana facility of its kind in Canada: using the converted waste of farmed fish (tilapia, in this case), as food for the nearby plants. The healthy plants, in turn, purify the water. The average cannabis-grower can produce a considerable amount of wastewater and can contribute to the well-documented harm of pesticides, fungicides, and fertilizers. Green Relief’s process is simple enough on paper; growing takes place within a concrete bunker in an earth-sheltered building, leaving the mini-ecosystems immune to the challenges of Canadian weather.

From a commercial standpoint, Green Relief’s yield is unheard of for most growers.“It’s the most prolific grow I’ve ever been a part of,” says LeBlanc, adding that the company is expecting 100,000 lb. in raw product this year; a target akin to that of industry giant Aurora Cannabis.

LeBlanc co-founded Green Relief with Warren and Lyn Bravo, a concrete contractor and a landscape architecture consultant in 2013. With the former’s construction expertise, the latter’s vision and a combined flair for innovation, it’s no surprise the 30,000 square-foot facility is an idiosyncrasy in cannabis production.

Aquaponics is more than a change of pace, though. LeBlanc and other advocates of the method (including Toronto’s own WaterFarmers) note that—for cannabis or otherwise— it’s the most sustainable form of agriculture today.

“We all know that water is going to be a huge commodity,” says LeBlanc, adding that he anticipates tight regulations on ground source water in the coming years. “We use a tenth of the water used in any other [growing] operation.”

The method also allows producers the luxury of avoiding harmful chemicals present in pesticides and fertilizers. It seems some of those benefits extend to the quality of the final product, too. “Our product acceptance is off the charts. Patients say it’s the smoothest they’ve ever smoked,” says LeBlanc. He says the degree of improvement dissipates with oils, however: “[Patients] say the product tastes better, though there’s not a lot of difference when it comes to oil.”

Aquaponics isn’t a catch-all solution, though. Operations manager Derek Bravo says that for a new voice in the industry, the odds are stacked high. “Because it’s so new in the cannabis space, there’s been a lot of trial and error,” he says. “Not just to grow them, but to grow them prolifically.”

Bravo pointed out that the facility is heavily devoted to research and development in its current state, and that the process has required consistent tweaking and vigilant surveillance to get the yield up to par. The wait times can be tedious as well: “One of the other drawbacks is how much time it takes to get the system started,” says Bravo. “It takes time to build up the [necessary] bacteria and nutrients. It can take anywhere from six months to a year.” Add onto that the cost of building and maintaining what is, in essence, a research facility and the labour of keeping ahead of the curve within a burgeoning technology, and the question of risk versus reward comes more sharply into focus.

As the enterprise broadens (the company recently received a handsome investment and have plans for a new 220,000 square-foot facility), Bravo says Green Relief sees itself expanding well beyond cannabis production alone.

“What we’re doing is a sustainable agriculture for anything,” says Bravo.

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