Grow Light vs Regular Light: Can Any LED Light be Used as a Grow Light?
Many indoor growers wonder if they can use any old LED lights as grow lights. They believe there is no difference between the two types of LED lights, as they both emit light visible to humans.
However, we cannot use regular LED lights as grow lights because they are created differently.
Regular lights only provide illumination; that is, they are designed as artificial light sources to illuminate your dark spaces. They consist of narrow spectral wavelengths and often do not have the proper spectrum to support photosynthesis.
Grow lights, on the other hand, are specifically designed to produce just the right amount of light for plants to photosynthesize.
We’ve listed a few areas where regular bulbs and grow lights can be distinguished:
Many LED grow light manufacturers conduct extensive experiments and study thousands of scientific reports on specific light color wavelengths so that they can produce the perfect grow light with multiple wavelength colors that plants need. They are: red and infrared, blue and ultraviolet, and green.
Of these colors, blue and red wavelengths are the most important to plants. Blue is responsible for green leaf growth and red is responsible for flowering and germination. To start seeds, grow lights should produce a lot of blue light, which is the most important factor in the early growth stages. When it blooms, the LED lights begin to emit a red spectrum to encourage plant growth.
Ultraviolet light guides plants to bloom, helping to kill bacteria. Plants don’t like green very much, so a grow light has less green elements, but it increases leaf expansion and stem elongation, which increases biomass accumulation (yield).
Infrared is invisible to the naked eye. It’s not as effective as red and blue, but it penetrates the leaves deeper, which increases cell swelling, so you end up with leaf count and increased shoot size.
Regular LED bulbs have lower light output per watt, which means more energy is required to produce the same light. Standard fluorescent lights are twice as efficient as regular bulbs, while LED grow lights are five times as efficient as similar regular bulbs.
As they sound, efficiency and efficacy are very related terms. In LED grow lighting, “efficiency” is a measure of how much light it can output for each input power (measured in watts) it receives. Efficacy, on the other hand, measures how many photons are emitted per watt of input light. Plant growth depends on the number of photons in the light received, not the intensity of the light. Because of this, efficacy is a more relevant measure for the indoor gardening grow light industry. When shopping for an LED grow light, it is important to understand its efficacy as it is the best way to compare the energy efficiency of your grow lights.
How to measure efficacy
Efficacy defines the ability of a grow light to convert power (watts) into photosynthetically active radiation (PAR) that the crop can use. Essentially, how efficiently light converts electricity into light is useful for photosynthesis. Today, the efficacy of LED grow lights is measured using Photosynthetic Photon Efficacy (PPE). PPE describes the amount of light a grow light produces from its input power. The metric used to measure PPE is micromoles per second per watt – simplified to µmol/J since watts are joules per second. Similar to an automobile’s miles per gallon (MPG), PPE is a generic rating and may not represent actual results from field devices.
The PPE listed by the manufacturer for grow lights does not take into account the light fixture arrangement, light fixture type or installation height and distance from the crop. While PPE is an important metric in determining how/should your cultivation facility operate, it does not reflect how many fixtures the facility will need to achieve the target PPFD.
Many common lights generate a lot of heat and should be hung no closer than 24 inches to avoid burning plants. They also need a ventilation system to remove heat from the room. Grow lights stay much cooler and can be placed about four inches above the plant for maximum effect. Additionally, modern LED lights are now designed to passively dissipate heat, either through the use of heat sinks or by transferring heat away from the diodes.
Grow light uses a pure aluminum alloy shell, which has good heat dissipation and extends the lifespan. Surface treatment is anodized, high thermal conductivity, ultra-fast heat dissipation and temperature reduction, and improve wear resistance. This allows your plants to grow quickly and happily. The full-spectrum LED grow light has no fan. It provides a quiet growth experience for growers.
LEDs offer more than just improved efficiency and cooler temperatures. You’ll also get more grow hours out of your LEDs — a lot more. LED grow lights typically last for 50,000 hours or more, whereas HID bulbs generally last 10,000 to 18,000 hours, depending on the specific type of bulb. When it comes to longevity, there’s really no competition.
The Full Spectrum
A major advantage of using LED grow lights is the huge spectrum of energy they provide. When you choose LED, you don’t have to worry about switching out lights as your crops mature through their growth cycle. Even better — you can actually install a system that’s tailored specifically to the type of crop you grow.
Are you growing up close? If so, that’s another reason to use LEDs, which have the distinct advantage of being able to fit into smaller, more compact growing areas. This advantage goes hand in hand with the lower temperature of LEDs – not only can you create a more compact grow room, but your crops can grow very close to the light without the risk of thermal burns.
Remember, thermal burns are not the same as mild burns – getting too close to any type of bulb puts your crop at risk of minor burns. Keep the crop within the ideal distance (12 to 18 inches) from the LED to reduce the chance of the crop being exposed to light burn.
Another benefit of going the LED route is that you can end up saving a lot of money. Both the federal government and local municipalities issue rebates on LED lighting systems to incentivize growers to invest in energy-efficient models.
How many hours a day should grow lights be on?
Every plant requires a different type and amount of light. Some do better than others in colder and less sunny areas. Plants that produce fruits and vegetables may need more light. Plan to turn on the LED lights for at least 14-16 hours a day. If possible, put them on a timer to make sure they run for 14-16 cycles.
Should I turn off the lights at night?
Yes, you should, and plants need rest too. Night gives plants time to eat, rest, and store enough energy. When photosynthesis stops, plants begin to breathe.
During the day, plants absorb enough light and nutrients to supply plant cells. At night, the process continues, but slowly converts energy into carbohydrates, which the plant stores for later use.
So basically, lack of light allows the plants to reset themselves and move nutrients to where they will be used when the light arrives the next day.
Can too much light kill plants?
Well, if your plants are in the vegetative stage, it’s okay to leave your grow lights on for 24 hours. It won’t kill your plants even though 24 hours of light is not recommended.
However, when it comes to flowering, too much light can prevent them from going into bloom, even if buds have already started.
What LED Grow Lights Should I Buy?
Although LED grow lights perform better than traditional lights, you should buy grow lights with the perfect combination of wavelengths for your plants.
As mentioned earlier, wavelengths contribute to various stages of plant growth, such as germination, vegetation, or flowering. For example, LEDs that are great for growing tomatoes may not be as effective for cannabis.
Many LED grow light manufacturers have introduced an adjustable full-spectrum LED grow light that produces different wavelengths to stimulate plants at different stages.
So, if you need to take care of your indoor plants with LEDs at different stages, buying a full-spectrum LED grow light or an adjustable light is a good choice.