“A key aspect of CPS is that in the
flowering room, there will be several
sets of plantings in different phases of
flowering and maturity.”
Where we last left off, we began to discuss the benefits of
supplementing carbon dioxide levels in our Continuous
Production Systems (CPS) growth chamber model. We had
a quick overview of some of the different types of CO2
enrichment systems and some choices with regards to the
necessary components to put it all together. By supplementing
carbon dioxide levels during vegetative growth, plants can gain
more stature with an increased number of branches, leaves and
potential flowering sites in less time. For the flowering area,
increasing CO2 levels during the light cycle will help accelerate
the flowering process creating bigger, heavier and denser
harvests of flowers and fruits in a slightly faster time frame.
Remember that experienced growers only begin to take on
supplemental carbon dioxide systems once the rest of the growing
environment is totally dialed in and functioning smoothly. If you
don’t have accurate and total control of temperature levels and
lighting (as well as other growth parameters), the increased CO2
levels will be of limited value to the crop.
As well, if your exhaust fans and intake, if applicable, are running
frequently, most of the extra CO2 supplied to the plants will
make it’s way out through the ventilation system before it has had
sufficient contact time with the crop to be of significant benefit.
A key aspect of CPS is that in the flowering room, there will
be several sets of plantings in different phases of flowering
and maturity. Different stages in the flowering cycle would all
benefit from different levels of carbon dioxide supplementation.
Of special consideration are ripening plants, which will
produce higher quality harvest with better flavors, aromas and
other characteristics when CO2 levels are not elevated too
highly. Ethylene is a hormone that is produced by the plant
to help promote the ripening process. Ethylene production is
inhibited by higher CO2 levels.
With the needs of all phases of flowering in mind,
supplementing CO2 levels to between 800 to 1000 ppm
(parts per million) as an average level in the flowering room
will provide the necessary boost to keep flowering plants in
overdrive without inhibiting the ripening process too greatly.
In order to facilitate a slight differential in CO2 levels between
planting stages in the flowering area, note the placement
of the water cooled CO2 generator in the area along with
“If you don’t invest in an accurate CO2
monitor/controller, you are only guessing
and rolling the dice with how much CO2 is
present for the crop at any given time.”
the placement of the probe that signals to the CO2 burner
controller. The area further away from the generator and very
importantly, the probe, should receive slightly lower CO2 levels
than the area situated closer to the CO2 supply and monitor.
The way you direct your air-flow away from the CO2 generator
can further help to keep CO2 levels slightly higher in one area
of the grow room versus others.
Some growers will wait until they have a few harvests under
their belts before installing CO2 systems to help ensure they
have the necessary budget available for the purchase of a
high quality and accurate carbon dioxide monitoring and
supplementation system. If you don’t invest in an accurate CO2
monitor/controller, you are only guessing and rolling the dice
with how much CO2 is present for the crop at any given time.
The monitor/controller featured in this series of articles is
extremely accurate, and of equal importance, it remains that
way for a significant period. Most monitors use a single beam
technology. As the filament of the infrared light that helps to
calculate CO2 levels begins to wear out, single units will be
giving less precise readings and, therefore, levels. The problem
particularly becomes compounded over time. The dual beam
units use an additional bulb to measure the light levels being
emitted by the infrared filament that actually measures and
controls CO2 levels. The second bulb measures and compensates
for the diminishing light output of the bulb that does the
“sniffing.” This way, CO2 levels and controls are much more
accurate, especially over a period of time.
The unit is also relatively unique in that it accommodates a
second optional probe, so one monitor can control two different
CO2 generators or generator and tank combos completely
independently, allowing for two zones of control in commercial
sized CPS flowering rooms, or for independent CO2 control
in a separate vegetative growth area. The probes use a CAT-5
network cable to connect to the controller, which can be kept
outside of the growing area. The CAT-5 network cable can be
extended for significant distances.
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