I’ve had the privilege of operating a couple million square feet of cannabis growing facilities. The differences from one operation to the next are significant; from schedules to teamwork to responsibilities, each setup is as unique as the crops they grow. However, I’ve noticed some common problems that “everybody knows” but somehow always come up. These issues are causing massive production problems with even the strongest cannabis grows.
A lot of growers don’t take the cleanliness of their work as seriously as they should. The surfaces look clean, but are they really? Microbial activity affects the electrical conductivity (EC) and pH within your nutrient delivery system.
These conditions can harbor all sorts of nasty biofilms and complex chemistries that can potentially cause nutrient fallout and/or increased “blooms” of microbiological activity.
This has the potential to affect the delivered nutrients and performance of the grow operation. Maintaining clean media, having proper handling and sterilization of the plant material is paramount to success within a regulated environment.
Most growers think “more in, more out,” but this is a dangerous mindset. Too much fertilizer — at any stage of growth — can cost a lot of money, both in wasted nutrients and potentially lost yield.
Over-feeding can cause nutrient buildup within the grow media, which may block other important nutrients, thereby creating lockout scenarios where the plants are not getting what they need to metabolize most efficiently.
What do we know and how do we know it? If you want to get the most out of your grow, you have to continually know your pH, electrical conductivity and microbial loads.
The basics are the easiest to let slip through the cracks, but they are highly important: runoff and media chemistry is vital to continuously monitor so that you don’t over- or under-feed your plants.
You have to know if you are contaminating the product, so know your microbial counts — especially at the end of the grow so you do not contaminate your harvest.
This issue can come up for many reasons, but usually it’s either the environment, plant handling procedures or not having proper standard operating procedures for cleanliness of employees and grow spaces.
Every grower needs to understand how all adjuncts given to the plants have both a cause and effect. Insects or wildlife may create problems in the form of coliform bacteria or E. coli in post-harvest testing.
The grow media must be properly maintained. Pairing the EC and pH with the runoff is critical to support your grow.
When you’re refreshing the media, maintain the science behind your process. If you provide a 2.0 EC media, your runoff ideally should be between 2.0 and 2.2 coming out the back end.
This way there is not an excess or deficiency of nutrients. Monitoring the runoff is a way to know you’re following best practices, as well as understanding what your plants need and don’t need.
Are you closely monitoring your temperature and humidity? The construction of your building or greenhouse seriously affects your ability to maintain proper environmental conditions.
These conditions affect the plants’ ability to convey the nutrients from the grow media to the plant, from the root zone, up through the stalks, shoots, petioles and leaves. The environment needs to be pretty close to perfect for the plant to grow perfectly.
There is not an “exact” number for all plants. This is dependent on the genetic profile of your plants and will change from one cultivar to the next. Some plants drink more than others, etc.
If I get away from the basics, I let go of control over my grow. By following these essentials, I retain the ability to manage and scale every plant to the best of its ability, both in yield and genetic expression. These are basic concepts, but even a basic mistake — or worse, laziness — can cost me the crop.
Darin Carpenter is a retired Army Ranger who has a degree in genetics, biochemistry and cellular biology. He is the former operations director for Tryke Companies and multiple cultivation/extraction facilities. He is currently the chief technology officer for Jungle Performance Brands and King Nutrients.