The distance at which you set up your grow light is important

The Inverse Square law which explains the relationship between the light intensity of a grow light, and the distance from the grow light, is a key concept to understand.

The inverse square law of light states that the intensity of the light decreases with the square of the distance from a light source. This means that if you double the distance from a grow light to your plants, the intensity of the light will be reduced to one fourth (½ x ½) of its original intensity. This is because the light is now spread over an area four times the size.


🔆Key takeaway: The intensity of light drops off surprisingly quickly the further you move the light source away. We recommend moving your grow light slightly closer if you aren’t seeing the expected results from your grow light (if you are not able to move it closer try increase the amount of time it is on slightly) In general a little bit of trial and error is needed to hit the perfect light intensity.


For a detailed guide on how far to set up your grow light bulb for optimal results, check out our guide on measuring light. It's packed with practical tips to help you get started on the right foot!

Written by Lorenzo Cadoux-Hudson

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