Low Oxygen: A New Method for Cannabis Cultivation

March 11, 2020
Abstract / Synopsis: 

An interview with Todd Bell about the experiments and findings his group is working on with controlled atmospheres in cannabis cultivation.

With the cannabis industry continuously expanding, new technologies and methods are coming forth to increase yields and production in cannabis cultivation. One such method involves using controlled atmospheres and low oxygen with the cannabis plant to increase yields and terpene levels. Here Todd Bell, Research & Development at Grow Controlled, LLC, goes into further detail regarding the experiments and findings his group is working on with controlled atmospheres.

Can you tell us a little about Grow Controlled LLC and the role you play in the cannabis market?
Todd Bell: Grow Controlled is an automation and controls company that specializes in custom built heating, ventilation, and air conditioning (HVAC) as well as refrigeration systems for cannabis cultivation and controlled atmospheres for short and long-term cannabis storage and preservation. Our primary focus is maintaining and optimizing environments for every phase of the cultivation and post-harvest process.

What have you found to be the most effective way to cultivate cannabis?

Bell: We’ve only cultivated in organic soil. Grow Controlled isn’t seeking the best or worst cultivation method, we’re focused on providing the perfect environment in the most efficient and sustainable manner possible.  Regardless of the method (hydroponics, aeroponics, or organic), the Grow Controlled system will streamline any indoor cultivation method. We have proven controls in greenhouse space as well as indoor grows. The Grow Controlled system provides the highest grams produced/KW of energy used possible.

How does low oxygen produce better yield from the plants?

Bell: To date, we are on the third cycle of low oxygen trials. The first two cycles were centered on programming for pinpoint environmental accuracy during all phases of the flower cycle. Plant health and yield was secondary. We did measure the liters of water being fed by irrigation and the amount of moisture being removed via dehumidification.

After two trials, we’ve seen the low oxygen rooms have a higher transpiration rate and 12% yield increase. The yield increase is nice, but the 28% terpene increase is the most encouraging. We’ve just started the trials and look forward to sharing the data.

How does this method differ from other methods in the industry?

Bell: Growing in low oxygen requires gas tight rooms with limited air exchange. The only fresh air introduced in our chambers is supplemental high efficiency particulate air (HEPA) filtered air added when necessary.  Many growing chambers are designed for ventilation with a fresh air exchange. The most common pests and pathogens are introduced via “fresh” air exchange. 

How do your products help reduce contamination (such as mold and other impurities)?

Bell: Biosecurity is the most crucial detail in a cannabis facility. Simply stated, all of our grow chambers and post-harvest technology is sealed and gas tight. Our insulated metal panels (IMP) are sealed with flexible seam tape and paint. The Grow Controlled HVAC and refrigeration system uses a four pipe, heat transfer coefficient (HTC) secondary fluid that eliminates the need for multiple standalone hanging dehumidifiers. Stand-alone dehumidifiers are microbial magnets that require constant maintenance and sterilization. Doors are a major contributor to contamination breeches. We offer three different door options that assist with biosecurity.