Lots more growers are starting to use grow lights, especially LED grow lights, but there’s a lot of confusion about exactly how to use them. One of the most common questions about using LED grow lights is how far they should be from plants.
In general, commercial grow lights should be 12-30 inches from the tops of plants. As plants grow, you’ll adjust your lights to maintain a consistent distance from the plants. However, the distance will vary depending on the wattage of your lights, the type of plant, and the amount of ambient light.
Light-emitting diodes (LED) lights are an efficient source of light for your greenhouse.
They’re extremely energy efficient, give off very little heat, emit both red & blue wavelengths of light, and generally last far longer than other types of electric lights.
In short, LED lights are the go-to type of light used by gardeners.
Since LED lights produce far less heat compared to other types of lights, plants can tolerate LED lights being much closer.
A general rule is that hydroponics led grow lights should be about 12-30 inches from the top of your plant.
As your plants grow, you have to change the height of your lights to accommodate the growing plants’ height.
Typically, most folks adjust the height of their grow lights using simple chains or cables, which allow the light fixture to be raised or lowered, depending on the height of the plants.
LED distance from plants and LED wattage
The main consideration for determining how close greenhouse grow lights should be from plants is the wattage of your LED lights.
Higher watt LED lights mean that you’ll need to have the lights further away from plants.
Conversely, lower-wattage lights can be moved closer to plants without harming the plants.
You can also play around with the distance, experimenting a few days at a time, and noting the effect on the plants.
For example, you could start with the lights a bit further away from your plants, then after a few days, move the light a few inches closer.
If you notice your plants wilting, looking burnt, the leaves looking dry or discolored, then move the lights further away.
It’s basically like looking at your plants to make sure you’re not getting them sunburnt.
Typically, when plants start flowering & producing fruit, you’ll need to move the powerful led grow light closer to the plant so it’ll have more light available for photosynthesis & producing flowers & fruit.
If your LED lights are too close to your plant, the plant will begin to bleach and develop yellow spots.
Since LED lights do not produce as much heat as other types of grow lights they do not burn plants as much.

However, you should still be cautious if the plant presents signs that it is being burned.