By Amari Emani

We can’t live without it. Air is critical to human existence and the same can be said of your cannabis plants. Managing air is critical to the proliferation of your cannabis garden in your indoor grow space–air quality, flow, temperature, humidity, exhaust, intake. There are several aspects to consider and each could be addressed in-depth in a series of separate lengthy articles and still there would be more to learn. And science is divulging new and different considerations every day as the shackles on research and development are removed from American cannabis science one state at a time. In this article we hope to establish a foundation of basic attention to detail that every cannabis horticulturalist can build on to ensure their plants have every opportunity to shine without limitations that may result from the absence of a basic understanding of air essentials.

Keep your air moving. Basic fans on stands or wall-mounted fans are your first ally to help move air around the room and combat a stagnant, hot and humid environment. During flowering, fans are especially critical to keep the air flowing to keep from creating dank moist areas that can be a breeding ground for spores and pests alike in the resinous depths of your colas. Filter your intake air to minimize the likelihood of introducing spores and other undesirables into the room from the outside environment. By adding more air input into the room than exhaust out, you can achieve a positive pressure scenario. The air in the room will thereby relentlessly push out of the room, helping to keep minute invaders at bay. Some folks even filter their outgoing exhaust air for smell control in clandestine ops and if this is your scenario, be sure to bend your exhaust ducting at least twice to keep light pollution from escaping the room too. Clandestine or not, when the CO2 is on we shut off the exhaust and intake fans and keep the ambient room fans on to keep the CO2 from settling to the floor.

We suggest keeping your humidity level between 45-52% and keeping your grow space clean–most of the enemies can’t flourish in a clean, dry environment. Room temperatures should vary according to cultivar, however most cannabis grows fastest and best when the leaves atop the canopy are 86 degrees F–so the fastest growth and ripening will occur in the mid 80’s. That said fast and aggressive growth is not always the goal for all growers, this grower included. Terpenes are hydrocarbon solvents that give the plant it’s smell and personality to the nose and palate. These solvents are volatile at relatively low temperatures. “That’s why marijuana odors waft through the air on warm days–the smallest terpene molecules evaporate into the room air at higher temperatures. By lowering the room temperature, terpene content is increased at the cost of slightly slower ripening (Ed Rosenthal).” As a compromise I lower my temperatures slightly toward the end of flowering, the last week and a half, to ensure max terps.

The end game with air is to make sure your ladies have ideal growing conditions, critical to proper growth. It is arguably just as important, especially in the Pacific Northwest, to stay on point with respects to mold, powdery mildew and other space invaders. Be sure to halt foliar feeding after week 2 of flowering to avoid excess moisture build up on the plants and in the air. Keep a nicely pruned canopy to allow for maximum air movement and circulation to minimize dank, dense proving grounds as your colas mature. There are fungicides and other products for use in preventative maintenance, but remember, someone will be consuming these plants and no one wants to ingest or smoke mold, mildew nor fungicide and even organic solutions kill your terpene profile. If you detect these microscopic intruders, we suggest you turn off your fans immediately to contain the outbreak and dispose of contaminated plants immediately.

There are a number of air purifiers on the market and some growers use ozone generators boasting of seemingly impressive benefits like combatting mold and predators, oxygenating roots, sterilizing and disinfecting the entire room. There are allegedly enough benefits to warrant a better look under the microscope, however ozone can be harmful to human health, causing damage to the lungs, so be sure not to over expose yourself to ozone molecules and besides, if ozone can be harmful to humans, let’s just face it, science has yet to weigh in on the potential reprecussions of ozone to your plants. According to Bill Widmyer, “What we do know about ozone and cannabis is ozone decreases your terpene levels.” Widmyer is new to the cannabis industry but Puradigm has been successfully implementing their solution on the basil horticulture scene, quelling mold proliferation and saving an industry that was losing 70-80% of their crop annually to mold.

What makes Puradigm unique over all other historical air purification products is the technology? Past generations are passive and require air to pass through their units to provide any benefits. The Puradigm technology is an active technology that expels highly charged, bi-polar ion clusters and advanced oxidation into all areas of your indoor environment protecting your grow 24/7. These high energy clusters float with your air movement to protect every inch of your room. Puradigm technology offers a solution to your problem with a proactive and preventative air and surface purification system. Their units offer an organic duplication of nature’s process indoors that is university tested and validated to be effective against microbials, mold, mildew, VOCs, and odors in the air and on surfaces without effecting your terps. The technology is certified to be safe and scalable for any indoor grow environment and vetted and tested to verify no adverse effect on terpenes or potency level and now installed and protecting over 700,000+ sf of cannabis grow rooms. The Puradigm solution is available direct to gardeners at–page.