As the popularity of the LED grow lights increases, distributors and manufacturers are inventing new concepts to capture the attention of consumers. Most production companies enjoy lacing scientific facts with a generous amount of marketing ploys in anticipation of customers pausing for a moment to become dazzled with the latest hype. There is a significant number of terms that find their way to the ears of customers everywhere, making it difficult to distinguish reality from marketing hyperbole.
One of the most frequently used methods marketing companies employ to attempt to get the attention of consumers is to talk about the spectrum & wavelength of the LED grow lights they sell. Here is a simplified explanation of what is essential and what is not with regard to using LED grow lights:
Understanding Light Spectrum
To understand the topic of light, one must familiarize himself or herself with the term “spectrum.” This term simply refers to the range of visible light wavelengths in the entire electro-magnetic spectrum. Apart from light which is visible, the electro-magnetic spectrum includes radiation(energy)from gamma rays, X-rays, ultraviolet, infrared, microwaves and radios and microwaves. Interestingly, the plural form of the term spectrum is not the frequently heard “spectrums,” but “spectra.”
At any rate, grow lights are primarily concerned with the visible spectrum although, on occasion, they use both the ultra violet and infrared spectra as well.
Facts About Wavelength
With regard to an LED grow light or other type of light, the term “wavelength” is speaking of the distance between troughs and peaks in a wave. Light wavelength behaves similarly to water waves with their peaks being close to each other or a good length apart. This is how the color one sees is determined, from the long wavelengths, which are red in color, to the shorter wavelengths, which are seen as blue. Each color along the spectrum is measured in nanometers ranging from 780nm, down to 380nm from red to blue/violet, respectively.
Plants derive all the energy they need to complete the process of photosynthesis and grow from visible light spectrum. Led grow light were developed based on this natural occurrence, which was studied by botanists and scientific researchers.
How Plant Growth is Promoted With LED Grow Lights
Although HID lights gravitate toward a specific end of the light spectrum–red/yellow for high pressure sodium, blues for metal halide–they emit a full visible light spectrum, similar to the way a common household lightbulb functions. Generally speaking, plants respond in a similar way to all light, but receive the most benefits from numerous red and blue wavelengths. Subsequently, they receive the least benefit from yellows and green, as the majority of this light is reflected back to its source.
Originally, manufacturers of LED lights were of the opinion that one band of red light and a single band of blue light were all that was necessary, and that in the right growth conditions, success could be achieved. While this may have worked on plants such as grass in limited testing conditions, it produced negative results or failed completely in more complicated plants such as tomatoes. However, companies did not stop manufacturing poorly designed LED grow light models in the early days of their production. It is for this reason many manufacturers are still trying to separate themselves from this stigma.
Necessary Wavelengths and Spectra for LED Grow Lights
Those who embraced LED technology early on, saw plenty of potential and fortunately for the general public kept encouraging further development of LED technology. They soon discovered that the first models were at least in part successful; they had a thorough understanding of the concept of red-blue light; however, there were still kinks to be worked out. It was determined that additional wavelengths were necessary to address the shortcomings of the earl LED models. When a PAR chart is observed, one can easily see that there are specific areas on the light spectrum where plants obtain almost all of the energy they require for the process of photosynthesis. Additional testing demonstrated that there are 2 specific, individual peaks in both the red and blue spectra and one distinct, smaller peak in the orange, meaning three light spectra are necessary in a total of five wavelengths–light bands.
The aforementioned scenario essentially means that the LED grow lights are perfect for full cycle growth of plants; from flowering to vegetative growth. Simply speaking, light from the spectrum’s blue end is needed for plant growth, and results in healthy, string plants featuring thick foliage. By way of comparison, orange and red lights are needed for fruit and flowering and fruiting, and the production of dense, large buds along all of the nodes that were partially created by blue light.
The Step Next in the Use of the LED Grow Light
While some manufacturers are still promoting their full spectrum lights and marketing various LED models, other producers are choosing to refine the modern technology used today. Some are of the opinion that the objective of LED grow lights is the fact that they function efficiently and produce the precise wavelengths necessary for photosynthesis. Most individuals realize that HID lights and the full spectrum light they produce is not efficient, although some companies still promote these models. Furthermore, the addition of excessive LED bands which only produce more inefficient light, is regarded by some as a step backward rather than forward.
No one knows precisely what the future has in store for LED grow lights; however, some companies do better than others with the production of such lights and the technology they choose. Thankfully, at least it is known that the industry will continue to benefit from scientific research and true innovation for many years to come.
If 630 nm is the best red spectrum, what wavelength is the orange that plants use?
Great site too !
642nm/667nm/680nm are the spectrums required for flowering and you are going to want to have UVB 420nm in there for massive trichome production as well