Cannabis can grow in any environment that fulfills the basic requirements of providing light, water, and air. This page is here to describe some of the typical configurations and key components for those attempting to grow in a new environment.
Outdoor
When growing outdoors a key consideration is when to plant seeds for optimum light and temperature conditions. It is best to know the DLI your plant will receive when choosing a location. You can check the DLI for a given longitude and latitude through the year on Suntracker. https://dli.suntrackertech.com/
Indoor
While growing indoors it is crucial to monitor and adjust the environment's temperature and humidity as there is no natural mechanism to regulate these factors. Data from environment sensors will give the best indication of if the environment is sufficient but there are alsosymptoms of bad environments that can be helpful in determining sufficiency.
Temperature and humidity
Raising humidity
Raising the humidity of your growing environment can be most easily achieved by adding an electric humidifier or diffuser to the space. Alternatively, placing a wet towel in the area will help to raise humidity.
Lowering humidity
Electric dehumidifiers are a simple option for lowering humidity but they may be too large for your grow area, a more compact option is to use a chemical dehumidifier. They are commercially available but can also be made from Epsom salts (Magnesium sulfate) or silica gel.
Raising temperature
Generally speaking, the easiest way to raise the growing environment temperature is to raise the temperature of the room it is in. If this isn't possible then raising the light intensity or adding an electric heater can help.
Lowering temperature
Temperature can be lowered by increasing the rate of airflow from inside to outside the growing environment, in other words, increasing ventilation. The light being used may also be adding to the temperature so decreasing its intensity, where possible, will lower the temperature.
Adding extra Co2
Very high levels of Co2 (>1,000ppm) can induce headaches and sleepiness[1] so be sure to buy a sensor to ensure you are exposed to safe levels.
To increase Co2 concentration to a high level in the grow environment the enclosure must be sealed to prevent the gas from escaping. Ventilation must also be reduced or disabled. There are two main methods of adding Co2: using a tank with regulator and tubing into the grow space or using a chemical reaction that produces Co2. A cheap reaction that can be used is a mixture of 2:1 water to sugar with a tablespoon of instant yeast. The rate of Co2 production will depend on the temperature.
Co2 is heavier than air so however it is attained it should be inserted above the canopy so that it falls onto the plant. Fans on the floor pointing upwards can also help direct Co2 from the floor into the leaves.
Example indoor environments
Tents
Cabinet
Spacebucket
An ultra simplistic design often utilizing plastic buckets. https://spacebuckets.com/template