LED grow lights quickly become the “go-to” option for many growers. After all, they are a very environmentally-friendly option, start up easily, provide full power almost instantly and help you save energy.
Why use LED grow lights?
Indoor crop cultivation always means more variables come into play compared to traditional outdoor cultivation. Indoor growing using LED grow lights can potentially give you improved plant growth and crop yields because you can easily manage certain variables to your advantage, such as light and heat intensity, as well as different spectrum specifications.
They can also help you reduce your carbon footprint and save a few pounds off your electricity bill, which is often a concern for marijuana cultivators.
Distance from the canopy
The latter’s growing needs govern the optimal distance between your LED light fixture and plant canopy. Unlike traditional indoor grow lights, LEDs can be mounted closer to your plants as they emit lower physical temperatures.
You are all set by following the manufacturer’s specifications for optimal height. But with that said, we can definitely recommend some general guidelines to follow:
Position your LED between 36 and 60 inches for seedlings, although this can vary depending on the power rating of your lights.
For the vegetative stage, place your LED grow lights between 15 and 24 inches from your plants. And, for the flowering stage, a distance between 12 and 20 inches would suffice.
However, if you’re growing clones, you may want to place your lights between 15 and 36 inches as these cuttings are not seeds and require treatment much like vegetative plants.
Monitor temperature and humidity
LED grow lights produce some heat, even though not to the same level as HPS fixtures. Therefore, you don’t want your ambient temperature to rise too much. Install a thermometer at the plant level to monitor temperature and humidity levels.
For instance, the flowering temperature is optimal between 26°C and 28°C at 40-60% humidity when using LED grow lights (using CO2, the temperature levels might be even 30°C), while vegetative temperatures may range between 25°C and 29°C at 60-70% humidity. Using LED lights, the humidity will be a bit of a headache to control in the flowering stage because they do not dry up the air as HPS fixtures do. A dehumidifier will be your best friend.
Know when to install multiple LED grow lights
Most LEDs cast light at a targeted beam angle (90° – 120°), making them brilliant as individual spotlights as there may be specific sections of your grow you want the light to focus on. This kind of LED has a lens on diodes that control the beam angle. The only con is that they decrease the efficacy of the LED light.
However, it’s generally better to have your light cast in a wide arc, which can be achieved by multiplying your grow’s total surface area with the ideal number of LED grow lights. This will lead to your lights overlapping and producing a more even distribution across your canopy, which is exactly what we want for an optimal yield.
Don’t overwater when switching from HID to LED
Many cultivators tend to overlook this when switching to LED grow lights for the first time, with often disastrous results. Here’s what you need to know.
Regular HID lights produce a lot of heat (way more than LEDs) and lots of infrared light. This ultimately dries out the plants and soil, which means more water needs to be used.
With LED grow lights, you must remember that they don’t generate any infrared light and don’t emit anywhere near as much heat as HIDs do, so you won’t need to use the same abundant watering approach as before.
Starting out with relatively lower levels of water, you should check every day to see how quickly it dries up and then add as necessary. Note how much water is needed and how much time it takes to dry out.
Choose the right light spectrum
More advanced LED light fixtures to have at least a few spectrum combinations for vegetative and flowering stages. If you are lucky to have one – you are one step closer to maximizing your yield.
Plants demand unique types of light for optimal growth at each stage, and even though this is attainable by going with full-spectrum LED grow lights, setting the perfect spectrum will help your plants develop optimally.
For example, more blue spectrum light is better when plants are vegetative stage, and more red is suitable for the flowering stage better.
LED grow light maintenance
LED lights for growing are still quite expensive. But in the long run, it’s worth every penny. Why? Because most of them will last more than 50.000 hours if you follow the specs sheets, but in reality, they last much more. The main thing is to follow instructions for maximum ambient temperatures and humidity levels. If your LEDs have lenses, then it is recommended to clean those lenses after each yield with a dry soft microfiber cloth.
