First and foremost, it's essential to follow each manufacturer's recommendations for their LED grow light placement, as each LED light is designed with a specific angle and height to cover a certain area effectively.
In general, there are wider, spread-out LEDs, often with a spider design, which can be placed closer to the plants due to their less intense, more dispersed light. These lose power quickly as the height increases. Conversely, direct HPS replacement lights tend to be more powerful and have a focused angle, requiring higher placement for proper coverage.
For fixed power level lights (non-dimmable), adjusting the light intensity at the plant level is done by raising or lowering the lights. The inverse square law applies here: increasing the distance by 3 feet results in nine times less light. Therefore, for non-dimmable lights, height adjustment is crucial for managing light levels.
For dimmable lights, such as California Lightworks SolarSystem and SpectraMax series, the lights can remain in the same position, and intensity can be adjusted using a controller. Specifically, California Lightworks recommends the following heights for their lights:
SolarXtreme Series:
- Veg: 24 to 36 inches
- Pre-flower: 24 inches
- Flower: 18 to 24 inches
SolarSystem Series:
- Veg/Pre-flower/Flower: 36 inches from canopy and adjust the spectrum based on growth phase
SpectraMax Series:
- Veg/Pre-flower/Flower: 24 inches from canopy and adjust the spectrum based on growth phase
For all three series, using reflective walls in a grow tent can allow for higher light placement as the light will bounce and provide even coverage. If reflective walls are not used, it's crucial to dial in the spectrum and get the lights as close as possible without burning the plants. Adjusting light height during different growth phases is also essential:
- Higher placement during propagation for lower intensity.
- Lowering during veg and flower stages for increased intensity, being cautious of potential burning.
For more detailed information, We provides resources on our website and YouTube channel, and offer direct support via phone, email or contact form.