Light: Difference between revisions

In ideal conditions, cannabis can absorb 1500 - 2000 μmol/s. For context, in California, the sun can emit up to 2000 μmol/s around midday. This means that the light source should ideally be powerful enough to deliver this intensity over the area the canopy will occupy. Equipped with a powerful and efficient grow light, you may be tempted to use as much power as you can afford, to increase yield - but this is often not the best strategy; leaves can be damaged by overexposure to light (and heat) which will decrease yield. To avoid this, slowly increase the intensity of your light over several days, by increasing power draw by 5-10 watts per day, observing the leaves regularly. Any yellowing leaves can be a sign of light stress. This may be accompanied by curling leaves which are a sign of heat stress, often caused by lights being too intense. Note also that seedlings require less light than flowering plants.