One of the main factors when placing the grow light should be the daily light integral for your plants. Which is the plant equivalent of calories for humans.
In other words, if you don’t provide them enough light your plants will start to lose energy and it is more likely to kill them. Another essential point is to know the optimal light duration for the plants you want to grow. Again it depends not only from the type of the plant, but also from its stage of growth. And not least the watts of the led bulbs of your grow light.
Best Grow Light Distance For Seedlings?
During the seedling stage you don't need to provide them more energy.
Most of the plants, no matter if they are edible or decorative, actually prefer more darkness during this period. So it would be better to stick to the normal cycle of 16-18 hours of light, and 6-8 hours of darkness.
The ultimate distance from the light to the plants should be around 24-36 inches.
Best Grow Light Distance For Edible Or Flowering Plants?
When it comes to edible plants, or the ones that produce flowers the situation is much more different.
Their DLI requirements are much higher and here is why you should place the grow light closer to the plants.
All plants producing fruits need a lot of energy and the ultimate distance from the light to the plant is around 3 inches.
These plants need more hours of light and if you want to keep them energized and strong in order to bloom, provide them approximately 12-16 hours of light.
Signs Showing You Are Keeping The Light Too Close
There are signs that will tell you that you are keeping the light too close to the plants. If you notice thin outlines on the outside of the leaves it would be better to place the light a little bit further in order to avoid damages on your plants.
If some of the leaves start curling up, it is also a sign that the plant is too close to the light. Good ventilation of the room could prevent your plants from these issues.