While everyone has slightly different ideas on the exact details when it comes to growing marijuana, most industry growers don’t vary too far from one another when it comes to the ideal cannabis growing environment. These are the desired ranges we hear most often when talking to commercial growers (and we talk to a lot of them).

Temperature Range: 72-82°F during lights on and 66-70°F during lights off
Root Zone Temperature: 67-68°F
Room Humidity: 40-60%
Light Cycle Length: 18 hours on, 6 hours off during vegetative growth; 12 hours on, 12 hours off during flowering
CO2 Levels: 900-1600 parts per million during lights on, none added during lights off

As always, it is important to find the “Goldilocks” zone for your plants. This means that your plants are getting the right amount of light, enough air flow, the perfect temperature and humidity levels, and are being properly fed.

Your environmental control system is one of the most important grow systems in the cannabis grow. Know where the air in your rooms is coming from – is it being shared between all the rooms in your grow (traditional A/C) or is each room isolated from the other (water-chilled cooling)? By isolating each room from the others, you will more easily be able to prevent the spread of pests as well as contain odors.

One thing everyone can agree on is that finding the proper mix of environmental controls, nutrients and knowledge can lead to magic – increasing your yields and the quality of your end product.