After lots of reading and "research" trying to find the perfect LED light to start my first grow, I came across lots of terms that I felt is important to understand, in order to pick the proper LED.
Terms:
LED: light-emitting diode
Light Spectrum: Light spectrum is the many different wavelengths of energy produced by a light source. Light is measured in nanometers (nm). Each nanometer represents a wavelength of light or band of light energy. Visible light is the part of the spectrum from 380nm to 780nm.
Infrared > 760nm
610< Red< 760
590< orange< 610
570< yellow< 590
500< green< 570
450< blue< 500
400<violet< 450
Ultraviolet< 400
Spectral distribution chart: The spectral distribution chart is a visual representation of the light spectrum produced by a lamp. It is a graph showing the relative intensities of a light source at each wavelength.These charts can be used to compare the energy levels of various light sources. They are the most practical way to compare the quality of light created by different light sources. The chart shows exactly which wavelengths of light (measured in nanometers) the objects are receiving.
HOW TO READ A SPECTRAL DISTRIBUTION CHART?
On the left of the chart is the percent of relative energy. The highest energy output of the light source is plotted as 100% Relative Energy. The 100% peak is used to compare the energy levels of all other wavelengths of light produced by that light source.
The bottom of the chart shows all of the wavelengths of visible light energy that the light source produces. For example, if a wavelength is at 50% relative energy, that peak has half the energy when compared to the 100% peak. Scaling each chart to 100% relative energy allows side by side comparison of light sources with different lumen ratings (intensity) or wattages. For example, a 1000W HPS lamp has more overall intensity than a 400W HPS lamp even though their spectral distribution charts are the same.
Lumens: In short it's the light intensity, however this measure alone is meaningless when it comes to how "good" or "bad" the quality of the light produced for the plant is. In other words it's a quantitative measure rather than quality measurement.
Photosynthetically active radiation PAR: is the amount of light available for photosynthesis, which is light in the 400 to 700 nanometer wavelength range.
PPF (photosynthetic photon flux), or light output: is a measure of the total PAR produced by a light source per second. However, because PPF is measured at the light source, the metric doesn’t accurately represent the amount of light that actually reaches the leaves of plants or the distribution of the light after its emission. That makes it a meaningless measure in grow lights.
Photosynthetic Photon Flux Density (PPFD): is a measure of PPF that reaches a specific area (m2) of a given surface; in other words a measure of number of photons in the 400-700 nm range (PAR spectrum) that falls on a square meter target. Because PPFD only considers the light that reaches plants, it is generally considered a better metric than PPF, and the metric is currently one of the best ways to measure and compare light intensities. However it's important to know at what hanging height were those PPFD taken; and the PPFD measurements at different spots from the light's covering area.
I am quite sure I missed more terms and vital measures that make a growlight good or bad, I hope some experienced posters can add.
_______________________________________________________________________________________
Some info I came across, that seemed important in picking an LED grow light, I don't know how accurate the claims are or how vital those points are.
1) White LED lights that represent the full light spectrum is better than broad spectrum or gap spectrum lights.
2) There are two types of White Lights;
2.1) Single LED that emits three primary colors of Red, Green, and Blue, multi-color white LED or RGB LEDs
2.2) Phosphorus type; phosphorus based semi conductor material that that converts blue or UV light into broad or full spectrum white lights ( phosphorus based white LEDs.
Claims are Single or RGB LEDs have more stable color, more efficient CRI and better luminous efficiency.
3) Green light spectrum, I got contradicting info some claimed it's not important for the plants therefore it's a waste, others claimed it's important especially for the shaded parts of the plants.
4) UV and IR are important to the plants.
______________________________________________________________________________________
Some questions I got after reading about lights
1) Since most grow lights have a coverage area of 4X4, why the huge difference in wattage? Do more intense lights have better canopy penetration and get to lower parts? Anyone with any info or comparisons done on this matter.
2) ideal PAR, PPFD reading for marijuana growth at different stages.
3) ideal spectrum distribution for different growth stages
4) for someone looking to achieve the highest yield per plant and not per harvest what spacing do you recommend, and light parameters do you recommend.
5) any websites or individuals that customize LED lights or does it have to be DIY.
________________________________________________________________________________________
Any info that would help making the best decision in picking a grow light would be appreciated. There are many brands out there and can't really rely on what the claims are.... picking the grow light has been a major headache lol
Ty all in advance
Terms:
LED: light-emitting diode
Light Spectrum: Light spectrum is the many different wavelengths of energy produced by a light source. Light is measured in nanometers (nm). Each nanometer represents a wavelength of light or band of light energy. Visible light is the part of the spectrum from 380nm to 780nm.
Infrared > 760nm
610< Red< 760
590< orange< 610
570< yellow< 590
500< green< 570
450< blue< 500
400<violet< 450
Ultraviolet< 400
Spectral distribution chart: The spectral distribution chart is a visual representation of the light spectrum produced by a lamp. It is a graph showing the relative intensities of a light source at each wavelength.These charts can be used to compare the energy levels of various light sources. They are the most practical way to compare the quality of light created by different light sources. The chart shows exactly which wavelengths of light (measured in nanometers) the objects are receiving.
HOW TO READ A SPECTRAL DISTRIBUTION CHART?
On the left of the chart is the percent of relative energy. The highest energy output of the light source is plotted as 100% Relative Energy. The 100% peak is used to compare the energy levels of all other wavelengths of light produced by that light source.
The bottom of the chart shows all of the wavelengths of visible light energy that the light source produces. For example, if a wavelength is at 50% relative energy, that peak has half the energy when compared to the 100% peak. Scaling each chart to 100% relative energy allows side by side comparison of light sources with different lumen ratings (intensity) or wattages. For example, a 1000W HPS lamp has more overall intensity than a 400W HPS lamp even though their spectral distribution charts are the same.
Lumens: In short it's the light intensity, however this measure alone is meaningless when it comes to how "good" or "bad" the quality of the light produced for the plant is. In other words it's a quantitative measure rather than quality measurement.
Photosynthetically active radiation PAR: is the amount of light available for photosynthesis, which is light in the 400 to 700 nanometer wavelength range.
PPF (photosynthetic photon flux), or light output: is a measure of the total PAR produced by a light source per second. However, because PPF is measured at the light source, the metric doesn’t accurately represent the amount of light that actually reaches the leaves of plants or the distribution of the light after its emission. That makes it a meaningless measure in grow lights.
Photosynthetic Photon Flux Density (PPFD): is a measure of PPF that reaches a specific area (m2) of a given surface; in other words a measure of number of photons in the 400-700 nm range (PAR spectrum) that falls on a square meter target. Because PPFD only considers the light that reaches plants, it is generally considered a better metric than PPF, and the metric is currently one of the best ways to measure and compare light intensities. However it's important to know at what hanging height were those PPFD taken; and the PPFD measurements at different spots from the light's covering area.
I am quite sure I missed more terms and vital measures that make a growlight good or bad, I hope some experienced posters can add.
_______________________________________________________________________________________
Some info I came across, that seemed important in picking an LED grow light, I don't know how accurate the claims are or how vital those points are.
1) White LED lights that represent the full light spectrum is better than broad spectrum or gap spectrum lights.
2) There are two types of White Lights;
2.1) Single LED that emits three primary colors of Red, Green, and Blue, multi-color white LED or RGB LEDs
2.2) Phosphorus type; phosphorus based semi conductor material that that converts blue or UV light into broad or full spectrum white lights ( phosphorus based white LEDs.
Claims are Single or RGB LEDs have more stable color, more efficient CRI and better luminous efficiency.
3) Green light spectrum, I got contradicting info some claimed it's not important for the plants therefore it's a waste, others claimed it's important especially for the shaded parts of the plants.
4) UV and IR are important to the plants.
______________________________________________________________________________________
Some questions I got after reading about lights
1) Since most grow lights have a coverage area of 4X4, why the huge difference in wattage? Do more intense lights have better canopy penetration and get to lower parts? Anyone with any info or comparisons done on this matter.
2) ideal PAR, PPFD reading for marijuana growth at different stages.
3) ideal spectrum distribution for different growth stages
4) for someone looking to achieve the highest yield per plant and not per harvest what spacing do you recommend, and light parameters do you recommend.
5) any websites or individuals that customize LED lights or does it have to be DIY.
________________________________________________________________________________________
Any info that would help making the best decision in picking a grow light would be appreciated. There are many brands out there and can't really rely on what the claims are.... picking the grow light has been a major headache lol
Ty all in advance