Are LED Lights Full Spectrum? | Can They Replace the Natural Light for Indoor Growing?

by Morgan

June 9, 2022

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LED grow light is a new vibrant technology gracing the indoor growth sector. This light can emit a wide range of spectra, giving indoor plants the experience of natural sunlight. LED grow light evolved from the traditional grow lights, combining red and blue lights to emit a pinkish-purple light. However, improvements were made to come up with full-spectrum LED grow lights. This light emits a wide range of wavelengths ranging from infrared to ultraviolet to mimic natural daylight.

However, you need to do your due diligence to ascertain if the full-spectrum LED grow lights are full spectrum. Some are labeled so, but they aren't. They may contain LED diodes that emit different colors (with specific wavelengths) to match the full spectrum.

This article is your complete guide to LED grow lights, full-spectrum light, and their benefit to indoor plants. We've also described the best diode combination for the best lights for indoor plants.

Read through.

Are LED Lights Full Spectrum? - The Ultimate Guide

No, LED lights are not full spectrum. Instead, LED lights produce light when an electron drops to a lower energy state, emitting the excess energy as a photon. This process happens when the electron crosses the PN junction.

However, LED manufacturers to strive to produce full-spectrum light in different color temperatures. But to do so, they tend to compromise the rendering of some colors.

What Is a Full-Spectrum LED Grow Light?

A full-spectrum LED light is a LED light with wavelengths ranging from ultraviolet to infrared, just like natural daylight. This light should appear white. However, a LED grows light can have white color, yet it is not full-spectrum.

Beware of your judgment as marketers can use this term for marketing purposes. For example, some may use the term to only mean LED lights with close resemblance to sunlight.

Why LED?

You might wonder why LED lights are still the recommended full-spectrum light despite fluorescent and HID lights being full-spectrum. The reason behind this phenomenon is simple; LED grows lights have almost all colors of light with different wavelengths essential for your plants at different growth stages.

Purple light on cannabis plants

Types of Full Spectrum LED Grow Lights

There are three categories of Full spectrum LED grow lights. These are narrow, broad, and adjustable spectrum LED grow lights. Let's see their details.

Narrow Spectrum LED Grow Lights

Narrow-spectrum LED grow lights have a purple or pinkish hue. This feature is because they are meant for the red and blue photosynthetically active radiation. They have a higher ratio of narrow-band LEDs.

Pink grow lights have been in use for horticultural use since the discovery of grow lights. A narrow spectrum is crucial in the greenhouse for the sole reason of photosynthesis.

Broad-Spectrum LED Grow Lights

Unlike the narrow spectrum grow lights, broad-spectrum LED grows lights have a higher ratio of broad-band LEDs than narrow-band LEDs. As a result, they have a white hue with no real white wavelength. The white hue results from mixing green, blue, and red wavebands.

These full-spectrum grow lights are essential in photosynthesis and the improvement o the general plant structure ensuring higher yields. They are recommended for indoor plants unless specified to use narrow-band lights.

Plant under white and purple lights

Adjustable Spectrum LED Grow Lights

Adjustable Spectrum LED Grow Lights are modern LED grow lights that can be adjusted to narrow or broad wavebands for precision. You can control its spectrum wirelessly, allowing your plants to have fast flowering times, improved structure, and more yields.

They are the closest to the sun in terms of spectrum range. They play a key role in indoor commercial growth and scientific research purposes.

Best Full Spectrum Grow Lights

Do plants need all light wavebands? Yeah, they do. However, at the time of photosynthesis, they only need PAR light. Therefore, getting a PAR-optimized light spectrum would save you an extra coin while keeping the plant health to the maximum.

So, the best full spectrum grows light should be PAR-optimized and adhere to the following features.

  • It should be compatible with your growth environment.
  • It should be of use to the plants at all growth stages. That is from propagation to finish.
  • It should be ideal for the specific plants grown.

various LED lamps

HPS and MH lights have been resourceful for a long period. However, they have some shortcomings. For instance, the HPS light doesn't have a blue light, while the MH light doesn't have a red light.

HID bulbs are another option. They do well in terms of the wavelength range. However, you'll benefit from the full spectrum in CMH bulbs only. This light is efficient in indoor plant growth as they benefit the plants with a full range of colors, making them highly efficient.

Fluorescent lights are another great alternative you can choose from. They do pretty well in small gardens. You need to get a fluorescent bub from your local store and light it up in your indoor garden. This bulb will save you on the cash you would have spent on buying extra lighting fixtures. However, the fluorescent bulb is ineffective in large-scale indoor growth. This is because they have less power to do so. Therefore, you'll need more bulbs which translates to higher power usage and production of much heat.

Problems With Full-Spectrum Led Grow Lights

Despite full spectrum grow lights being optimized for indoor plant growth, sometimes this may not be the case. For example, you might find a grow light specified as full-spectrum light, yet it isn't.

Besides this problem, several other issues are associated with full-spectrum grow lights. They are listed below.

  • These lights are not optimized for plant growth.
  • They encompass the complete solar spectrum
  • Full-Spectrum grow lights aren't the same as natural sunlight.

Let's look at these issues in detail.

Full-Spectrum Grow Lights Optimization for Plants

You'll realize that many full spectra LED grow lights do not have the required waveband for proper plant growth. This feature happens despite their white color, which mimics the natural full spectrum daylight.

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LED strip blue

Plants need electromagnetic radiation wavelengths between 400nm to 700nm to carry out photosynthesis. Many would have expected the full spectrum grow lights to have these capabilities. On the contrary, these lights produce wavelengths not tailored for photosynthesis. Plants need PAR light spectrum. It never cares how bright the light is.

Still, many LED grows lights manufacturers develop lights with visual appeal rather than orienting them to meet the requirements of plants.

Full Spectrum Grow Lights and the Full Solar Spectrum

The theoretical approach to the full spectrum of grow lights can easily make you think they are the same as natural sunlight. They are not. Neither do these lights relate to the natural daylight nor do they have the same benefits as the sun. So, don't expect your plants to develop that well, as would have been the case with natural sunlight.

The solar spectrum has all the PAR, essential for photosynthesis, visible light, and many more other benefits, which we can't see with our naked eyes. This may include UV radiation, which has several benefits to the plants.

The solar spectrum has more than we can see, experience, or perceive. Therefore, developing light or anything to replicate it would be costly, time-consuming, and nearly impossible.

The Sun Is Dynamic, but Full-Spectrum Grow Lights Are Not

Assuming that the light technology succeeds in creating a sun's replica, the new creation will not have the same benefits as the sun.

The sun keeps on changing its position. Also, changes in weather patterns directly or indirectly impact the sun, affecting the intensity of its rays reaching plants. This feature implies that plants will receive sunlight at different times of the day, translating to different impacts on the plants.

Plant in a pink light

On the other hand, a full spectrum LED light does not change position when hanging in a grow room. Neither is it affected by prevailing weather conditions. This feature means that the intensity and effect of the grow light on the plants will remain unchanged no matter the time of the day.

Comparing the two, it is clear that the sun is more dynamic than the full spectrum LED grow light. Different light intensities trigger various aspects in plants, and the sun makes this possible.

Full Spectrum White LED Grow Light

A white LED diode is most likely to be full-spectrum. However, this isn't the case, always. You can craft a white full-spectrum LED grow light using white diodes or a combination of a white diode and other color diodes. This feature will allow this grow light to produce a white color, with a full spectrum of visible light.

Blue-purple LED lights and plants

How to Create White Light

Full-spectrum grows lights use a phosphor coating. The phosphor coating converts light from a single narrow wavelength range to a wide wavelength range. You can achieve this feature by covering the original color with several other colors. For instance, you can use red and green or red and yellow phosphors to cover a blue LED grow light, ensuring you achieve a wider and longer spectrum.

However, you should remember that not all white LED grow lights are full spectrum. However, you can determine if a light is a full spectrum or not by evaluating its color rendering index (CRI). The CRI determines how much light is close to the natural sunlight. Therefore, for a LED light to qualify as a full spectrum, it should have a higher CRI, which indicates it closely resembles the sun.


What Is the Spectrum of Led Light?

The spectrum of LED light is between 380nm and 740nm. It is optimized for the warm visual appeal of orange to red wavebands.

Is White Led Full Spectrum Light?

White LED lights have a broad waveband of lights. It has all spectrum of visible light, which resembles the sun. Thus it is a full spectrum light. However, it does not have the same benefits as the sun.

Where Can I Find More Information About Led Lights?

You can learn more about LED lights by visiting the website.

What Are the Benefits of Using Full-Spectrum Lights?

The full-spectrum lights have the following list of benefits.

  • It boosts the plants' growth
  • Improves the plant yields
  • Improves and fastens photosynthesis, resulting in rapid and healthy growth
  • Improves the plants' health

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About the author 


I discovered the benefits of Cannabis at a young age in 2002, with years of trial and error, my knowledge grew just like my plants. As my love for cannabis unfolded I began to teach and learn, trying to gain as much information and practical growing experience.

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