- Seedling: cannabis plants need 200–300 µmol/s.
- Vegetative phrase: cannabis plants should absorb between 306 and 617 µmol/s with 18 hours of light per day.
- Flowering phrase: cannabis plants should receive between 460 and 925 µmol/s with 12 hours of light per day.
You don’t need to adjust the distance between your lights and plants if the light intensity your plants are now receiving falls within the aforementioned range. It would be necessary to move the grow light closer to the plants below this range. Moving the grow light farther away from the plants would be necessary for anything above this range.
