58 HIGH TIMES I OCTOBER 2019
CLEAN WATER
Shropshire and his team continued showing me some of
the technology deployed to ensure successful harvests
under strict conditions. With a multiple pound-per-
light average yield, Big Island Grown is producing large
amounts of medicinal-quality cannabis while dealing with
some intense constraints and restrictions.
The farmers at Big Island Grown start with a reverse-
osmosis treatment of spring water from a source located
on the farm and grow solely in coco coir with some perlite
mixed in. They use a proprietary blend of organically
derived food-grade liquid nutrients with a Hanna fertiga-
tion system utilizing drip irrigation with two emitters per
pot for redundancy.
Lighting consists of Dimlux double-ended high-pres-
sure sodium (HPS) rigs with checkerboard double-ended
ceramic metal halides (CMH) on Dimlux Maxi controllers.
Rotators raise and lower the lights easily.
Plants go from cuttings to the flowering stage in just
four weeks. After they’re cloned, they go right into six-
inch pots in a high-humidity environment. The pots have
their bottoms cut out to avoid transplant shock in the
next stage. Once rooted and vegged for three weeks, the
plants are placed directly into 1.76-gallon flowering pots
and start the budding stage.FRESH AIR
When I visited, Big Island Grown was utilizing 17,500 square feet of
the facility, in which 32 strains were growing in three 2,000-square-
foot flowering rooms. With ambient humidity in the area typically
around 90 percent, the crew has to use cutting-edge clean-room
technology to ensure a pest and pathogen-free environment.
“The key to this level of environmental mastery is positive air
pressure,” Shropshire explained. “The flowering rooms are posi-
tioned in the center of the building, and all incoming external air is
pumped through a HEPA filter into a thermal buffer zone that steps
down the temperature [and] provides cooling and dehumidification
to the air. That air is then pushed into the tightly sealed rooms at
very low CFU [colony-forming unit, a measurement of biological
non-contamination], providing a resistance against any airborne
pathogens or incoming insects.”
In fact, the doors popped open quite strongly due to the internal
pressure, so care had to be taken when entering and exiting the
rooms. Multiple Quest dehumidifiers, ultrasonic humidifiers, and
three-ton LG split AC units are placed throughout the growing
rooms for redundancy. All of the equipment is connected through
a series of sensors that monitor CO 2 , temperature, pH, humidity,
and power. A Growtronix computer “brain” system makes real time
adjustment from sensor readings to ensure that the vapor-pressure
deficit is dialed in at all times throughout the different stages of
cultivation.Pristine
cultivation
facilities grow
clean cannabis.