An example Bill gives is how a 400w HPS lamp would be inadequate for the grow room, but a 600w would give plants the amount of light they require (between 350 – 500 watts per square meter).
Next Bill talks about the importance of correct ventilation and how plants need air to be sucked out from underneath them. The volume of your grow room is calculated as Height x Width x Length, and Bill explains that the fan you choose should be capable of extracting this volume of stale air from your tent/room every 3 minutes, replacing it with fresh air..
These formulas may seem unnecessary to some people and are often overlooked, especially by bedroom growers. Take the time to apply the relevant science, and the environment in your grow room will be spot on.
The right amount of light and ventilation for your size of growing area is key to obtaining good results and bigger yields. Next: What Size Carbon Filter?