\t\t\t\t\tCO2 Info \t\t\t\t \t\t\t\t \t\t\t\t\t\t \t\t\t\t\t\t\t \t\t\t\t\t\t\t \t\t\t\t\t\t \t\t\t\t\t\t \t\t\t\t \t\t\t\t\t \t\t\t\t\t\t \t\t\t\t\t\t\tAlmost all living beings are dependent on light of satisfactory quality. For humans, that means that sufficient oxygen must be present in the air, and that the air is not too polluted. For plants, and thus also for cannabis, it means good air quality, enough carbon dioxide (CO2), and not to much pollution. Relative humidity (RH), and temperature also play a large role in the growth of plants. Studies indicate the potency of buds goes down as the temperature goes up, so it is important to see that the plants do not get too hot during flowering cycles. The amount of CO2 in the open air is approximately 0.03 to 0.04%. The amount of carbon dioxide is also expressed in parts per million; ppm. 0.03% is equal to 300 ppm. There are differences in the CO2 needs among plants. By raising the CO2 content, growth can be accelerated. The law of diminished returns still holds true, however. Raising the CO2 level has limits, but at approximately 1500 ppm (0.15%), good results (a faster growth) are generally achieved. Above 1500 ppm, the effect of a higher percentage of CO2 decreases. A high concentration of CO2 is poisonous even for plants. A CO2 concentration of 1800 ppm or more is deadly for most plants. . In principal, the total air content of the room must be exchanged every 2-3 minutes. Using for example a grow room 3 meters long, 2 metres wide, and 2 metres high (12m³), this means that the ventilator capacity must amount to 30 x 12 = 360 m³ per hour. A standard bathroom ventilator can only handle up to 100 m³ per hour. Many growers ventilate their rooms with table fans. The point is the control of the temperature as well as the circulation of the air with sufficient carbon dioxide. Table fans are primarily intended to keep people comfortable on a hot summer day. They are much less suited to run continually for heat removal, and for CO2-content maintenance. Table fans have a tendency to melt with intensive use. You can imagine the consequences: not only the danger of fire, but also massive plant death. There are, of course, plenty of fans on the market which will take care of proper ventilation. These have been specifically designed to be able to run continually. The CO2 content in the grow room can also be heightened by adding CO2 from a tank. If the system is set with a timer clock, the desired amount of CO2 can be regularly released. Work with care, because you don't know how much CO2 is in the room at any given moment. An overdose can easily occur. To prevent this, it's sensible to ventilate the area well before each CO2 'injection'. The most professional option is to use a CO2 controller. This apparatus continually measures the CO2 content in the room. When the programmed minimum value is reached, CO2 is automatically added. If the programmed maximum is exceeded, the controller turns on the ventilating system. If CO2 is added to the room via a tank, or a controller, cultivation can take place at a higher temperature. Carbon Dioxide (CO2) levels should be high, particularly during the FLOWERING PHASE . Growth rates can be increased dramatically if the CO2 level is near 700 ppm. 300 ppm-(Outside Air) (Ideal)-1500 ppm,5000 ppm= (Death). CO2 is cheaply produced by burning Natural Gas. However, heat and Carbon Monoxide must be vented to the outside air. CO2 can be obtained by buying or leasing cylinders from local welding supply houses. If you find that you are making lots of trips to the supply house, complain that your "buddy" keeps leaving the cylinder valve open all night. This should provide a plausible excuse. (ideal temperature is 85 degrees for a room running co2 @ 1500ppm) (70 degrees sufficient for 800 ppms.) the amount of light needed for plants to use co2 in concentrations of 1500 ppm 7500fc (80,400 lux). \t\t\t\t\t\t
I've done grows with and without CO2. A CO2 system is largely a waste of money. You can increase yields some but it's not worth the cost.