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Carbon Dioxide (CO2) Explained

Carbon Dioxide Molecule
Carbon Dioxide Molecule

Many gardeners, indoor or greenhouse don’t utilize a tool well used in commercial agriculture. We humans exhale the very gas vital to a living plant’s existence; of course the opposite being true that plants output oxygen for living people to breath. That being said, have you ever heard of talking to your plants? With each breath exhaled or whispered over a plant’s leaves CO2 wraps around their foliage ready for up take.

So just how does one supply their garden environment with boosted levels of CO2?

First lets discuss a little about CO2. PPM stands for parts per million and is the scale used for measuring CO2. In ambient nature CO2 exists at about 350 PPMs, however, in an ideal garden or greenhouse plants thrive best with 1500 PPMs. CO2 is also only useful during the photoperiod of growing and should be shut off at sun down or lights off. Because CO2 is heavier then air the output source or CO2 emitter must sit higher then the plant canopy in any garden.

In my ventures into the gardening world I have heard many growers talk of using dry ice as a CO2 source in their garden. It is true that dry ice produces CO2, however, the amount put off in addition to the inconsistencies experienced with dry ice leads me to recommend leaving this method for your friends to experiment with. For those wishing to avoid the sizable investment into a complete CO2 system, Supernatural nutrient company presents Excello Fizz, the CO2 puck! This little guy is perfect for boosting ambient CO2 levels in small gardens 6x6x8 or smaller. Simply add water to a small bowl placed as high as possible in the room and the puck slowly dissolves over the day into a viable source of CO2. Remember: because CO2 is heavier than air, it’s source whether an Excello Fizz puck or hose emitter must always be placed above your canopy of plants.

The bottle and tank system utilizes liquid gas compressed into a bottle hooked to a regulator that controls the output via the solenoid and flow valve.

The solenoid is attached to a power cord that triggers the release or retaining effect of the regulator. The flow valve controls how much gas is released from the bottle after the solenoid is powered open. The instruction manual offers a few calculations on how many cubic feet your room is, and its corresponding rate to set the flow valve to. The power cord for the regulator is plugged into a timer that controls how often the regulator emits CO2 into your garden. If your garden system operates with a 24-hour exhaust fan some re-engineering to limit the need of that fan must occur. CO2 is useless and expensive if constantly sucked from the garden atmosphere. Using an air conditioner, air or water cooled light reflectors to combat heating issues is advised to decrease fan usage.

For those wishing to avoid refilling CO2 bottles the propane or natural gas burner is advised.

Both units can be hooked into an existing gas supply within your home or branched off to the outside green house. A CO2 burner hangs 18 inches off your ceiling (18 inches of clearance must be maintained on all sides of unit due to open flame) and has a pilot light. Hooked up to a digital reader and controller the CO2 generator releases gas that is ignited via the pilot light and burns off of 1 to 8 burners. The burnt natural gas or propane results in CO2 boosting to 1500 PPMs before the reader/controller shuts the gas supply to the generator off. Using a CO2 generator increases temperature, however, it is ideal for gardens larger then 8×8 requiring massive amounts of CO2 in a quick manor. With proper temperature control generators are great for small gardens, as they require no tanks to refill if plumbed off an existing gas main. Propane generators can also operate off BBQ style propane tanks.

A variety of different meters are available to gardeners. The CO2 control wizard is a plastic syringe growers fill with ambient air from their garden and then blow through a glass rod indicating with a purple mark how many PPMs of their garden air is CO2. This unit is an inexpensive method for gaining insight to the garden climate or testing the accuracy of digital meters. The PPM-3 manufactured by CAP both reads the CO2 levels by “breathing” the garden environment and controls output from a regulator or generator. The PPM-3 boosts CO2 up to a desired level and shuts either regulator or generator off until PPMs again fall below set limit. CAP also makes a unit called the FUZZY LOGIC, which activates the generator or regulator as PPMs of CO2 begin to drop, maintaining a more consistent level of CO2 during the photoperiod. Digital controllers such as the PPM-3 and FUZZY LOGIC take the guessing game out of gardening with Co2 ensuring that your plants live in the best environment possible.