Nowadays, instead of using traditional HID and T5 fluorescent lights, more and more growers choose to use LED grow lights. Compared with HID light, LED grow lights emit less heat, which means that the proximity between LED marijuana grows lights and canopy is different from that of traditional grow lights. It is also important to learn how the optimal distance between lights and plants affects plant growth at different stages.
For seedlings, the LED marijuana grow lights should usually be installed between 24-36 inches above the plant canopy. However, it depends on the power (wattage) of the light. Put the LED grow lights at the farthest position (around 36 inches) from the seedlings, which can keep the heat and light intensity at a low level and help prevent the seedlings from drying out. Once the root begins to sprout, the light can be moved closer (usually in the first 2-3 weeks).
At the plant growth stage, the LED grow lights should be placed 12-24 inches above the canopy. At this stage, photosynthesis needs more light, so the light source should be placed near the plant.
As plants enter the flowering period, the demand for strong light decreases. The top leaf of the canopy should be 18-24 inches away from the light source to produce flowers. It is at this stage that the height of the plant increases and the fruit grows. Depending on the light and the way you want crops to grow, you don't need to change the height of the light during flowering, especially when you don't want tall plants.
At the early stage of growth, seedlings are fragile and require a low level of light intensity. This means that it need not increase the light intensity prematurely, because the seedlings will multiply more gently. According to the intensity of the light, the grow lights can be safely kept at a certain position between 24-36 inches from the surface of the soil.
Marijuana cloning is a process in which cuttings of mature plants are used to plant another new plant of the same kind. The distance of LED grow lights above the clone is different from the height required by the seedling. For cloning, they will need high-intensity light to start to grow. Depending on the light intensity and maturity of the plant, the distance between 14-36 inches above the canopy may vary greatly.
As plants grow, their needs change. After the nutrition stage is completed, the plants enter the "flowering" stage. For mature factories, plants have become necessary for promising development.
At the flowering stage, the LED marijuana grow lights should be located between 16-36 inches from the plant canopy. Moving the light closer will increase the light intensity, thus maximizing photosynthesis. However, if lights are too close to the top of the plants, it may lead to the expansion of the growth range or even destroy the plants.