The Mayans and Aztecs used aquaponic growing methods hundreds of years ago, so there’s really nothing new about its built-in superiority to growing in dirt. Yet there’s a feeling many share that the costs of such a facility can be prohibitive. So we were delighted to see that Thumb Genetics of Lansing, Michigan recently opened its books to reporters and shared many of the figures that put using aquaponics for cannabis growing into perspective.

Aquaponics is all about economic efficiency. Once you’ve filled your water tanks and stocked them with fish, that’s it. There’s zero need for pricey fertilizer or expensive chemicals, because all the nutrients the cannabis plants need comes from the waste the fish excrete. The water is constantly recycled. In fact, the only regular expense is fish food, which is remarkably cheap to buy … about $80 a month in their estimation … and occasionally, having to add new small fish to replace older fish whose digestive systems have notably slowed.

Thumb Genetics is a 43,500 square foot facility, located in a former Walmart distribution warehouse in an industrial park. Interestingly, they have other grow facilities as neighbors using traditional dirt methods — and are happy to compare the two. For example, their next‑door neighbor has dozens of air conditioners on their roof and a power bill approaching $50,000 a month. Thumb needs only three air conditioners because of the water’s cooling properties, and their power bill has yet to hit $8,500.

The facility maintains three grow rooms, each with 250 plants. Depending on the strain, this equates to about eight ounces of cannabis per plant, every 8 to 12 weeks. The aquaponic method allows Thumb to have a shorter grow cycle than its dirt-based neighbors, averaging about one week in their favor.

The system contains 10,000 gallons of water, parceled out between 4-foot tall water tanks each holding 1,200 gallons. They have about 1,600 fish in total, and use tilapia because they will not breed so long as the water temperature is maintained below 82˚. Without any need for pesticides or antibiotics, the facility qualifies for the organic label, which they believe is an important product differentiator.

While they admit their up-front costs were three to four times greater than dirt facilities, they expect to be winners in the long run. Their facility cost around $4 million to start up, while their neighboring dirt facilities were around $1.25 million. However, with their cost of operation so much lower, and their expectation that the price for cannabis will drop, they consider themselves in an ideal position to succeed — and are already planning expansion into currently empty building space to have nearly 6,000 plants.