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All You Need To Know About The Full Spectrum LED Grow Lights
By Rene June 13th, 2022
All You Need To Know About The Full Spectrum LED Grow Lights

In daily life, you may hear about the term " Full-spectrum, Full spectrum LED Grow lights, and the benefits of full-spectrum lights. These are not new, but because there is no unified and recognized definition for these terms, It is difficult for us to understand all. By the way, we may don’t know if the benefits claimed are true or not. After reading this article, You will have a better understanding of full-spectrum, full-spectrum LED Grow lights, and the benefits of full-spectrum lights.


1、What is a full spectrum ?

2、What you need to know about full spectrum led grow lights ? 

3、Full Spectrum LED Grow Lights Myths

1、What is a full spectrum ?

The term “full-spectrum” is nothing new and was introduced around the 1960s. This is a marketing term created by light manufacturers in the lighting industry to describe the characteristics and uses of a certain type of light.

1) How did light manufacturers get the inspiration for the term “Full-spectrum”?

What is full spectrum grow light? The answer is the solar spectrum.

Stefan Graf, director of Illuminart in Ypsilanti, Mich., once said.“The only true full-spectrum light source is the sun”.

As we can see,this is the spectrum of the Sun.

From this solar spectrum, we can see that :

(1)The Sunlight has a broad wavelength, covers visible light (red, orange, yellow, green, blue, Indigo Violet), and contains infrared and ultraviolet light.

(2)The visible light spectrum of sunlight is continuous.

The visible light spectrum shows the spectrum of red, orange, yellow, green, blue, and violet in turn.

2) What does a discontinuous visible light spectrum look like?

Take the spectrum of blue-red light for example. This is a discontinuous visible light spectrum. The visible light spectrum presents only the blue and red light, lacking orange, yellow, green, blue, and purple lights.

(3)The ratio of wavelengths in different ranges of visible light is relatively balanced

As we can see from the figure above,there are no gaps, drops, or spikes in the visible spectrum.

3) What does the one that is not balanced look like?

There are gaps, drops, or spikes in the visible light spectrum.

Now abstracted from the characteristics of the solar spectrum, strictly, a full spectrum should have a broad wavelength, covering red, orange, yellow, green, blue lights in the visible spectrum and a small amount of infrared light and ultraviolet light in the invisible spectrum and no gaps drops, or spikes in the visible lights spectrum.

However, in real life, it is difficult to make a spectrum that totally copies solar spectrum,meeting all the conditions above.

So If a spectrum is continuous, and has a broad wavelength covering visible light and invisible light, then it is called the “full-spectrum”.

2、What you need to know about full spectrum led grow lights ?

What does full spectrum grow light mean? There is no standard definition for“full spectrum led grow lights”.

Light manufacturers will create their full spectrum light wavelength based on their customer's needs.

In general, a full spectrum led grow light is closest to the sunlight with  "full-spectrum", Correlated color temperature grade is 5000K-7500K, and Color rendering index close to 100.

CCT: Correlated color temperature is a way to describe the light appearance provided by light. The CCT of the full spectrum light is usaually between 5000K and 6500K. The sunlight at midday is about 5600-6500k. the higher the temperature, the bluer the light, and the lower the temperature, the yellower the light.

CRI: Color rendering index is a standardized test developed by lighting manufacturers in the mid-20th century. It refers to the ability of the light emitted by a light source to reflect the real color of an object. The CRI of a full-spectrum light is about 96. The CRI of sunlight is defined as 100. The closer the CRI is to 100, the closer the light is to sunlight.

Full-spectrum lights are used in the fields of human health, plants, microorganisms, identification, data transmission, and so on.

Take LED grow lights as an example

Lack of sunlight will retard the growth of most plants. However, The plant growth light can expose more light to the plants when lacking light especially indoors or in winter. For most growers, there are many kinds of plant growth light to choose from, the most common ones are red-blue light、HPS growth lights and led full spectrum lighting.

(1) The Red-Blue Grow Light:

The red - blue growth light is made out of LED , which has the advantages of low energy consumption, being customizable for specific plant and giving off almost no heat.

It provides blue light with wavelengths between 450 - 495 nm、red light with wavelengths between 620-630nm.

  • Blue light can improve stems and leaves growth

  • Red light can improve flowers blooming, blossom and fruit

As shown in the figure below, chlorophyll (a) chlorophyll (b), and Carotene absorb lights mostly in the blue and red bands of the visible spectrum. In other words, blue light and red light are the most important lights for plant growth.

The red-blue light aims at providing the most needed lights(red light and blue light) for plants to make sure that they can better go through the process of photosynthesis and have the best growth state.

(2) HPS Grow Lights:

HPS(High-pressure sodium) grow light is a kind of gas discharge light. It uses sodium in the excited state to produce light. It has been used in agriculture for many years.

The color of the light is yellow. The price is relatively cheap and can provide many lights as the full spectrum LED grow light does, but relatively more red light and less blue light than the full spectrum led grow lights for indoor plants.
It is capable of producing a huge quantity of light, which is very important for flowering. In fact, because of this, a lot of farmers preferred HPS lights for years.

(3) Full Spectrum LED Grow Lights

Like red-blue growth light, the full-spectrum LED grow light is made out of LEDs. Growers use it to grow plants mostly in a greenhouse and indoors such as agricultural research institutes, agricultural ecological parks, large office places, etc.

As shown in the figure below, the full spectrum LED grow light aims at providing light resembling sunlight.

The spectrum of full-spectrum LED grow light is continuous ( there are red, orange, yellow, green, blue lights in the visible spectrum ) and has a broad wavelength (it not only covers visible light (red, orange, yellow, green, blue, Indigo Violet lights) but also contains a small amount of invisible light ( near-infrared light(700~ 2,000nm)and ultraviolet A light(320-400nm))

because of the technical restriction of LED industry, there are gaps, drops, or spikes in the spectrum.

What is the difference between full spectrum LED grow lights and red-blue LED grow lights?


Full spectrum LED grow lights offer a comprehensive range of wavelengths, including green, infrared, and ultraviolet light, beyond the red-blue spectrum. This diverse spectrum provides plants with a more complete and balanced light source, supporting various growth stages and enhancing overall photosynthetic efficiency.


Full spectrum grow lights tend to be pricier compared to red and blue lights due to their broader range of wavelengths, mimicking natural sunlight. The increased cost reflects the advanced technology and comprehensive light spectrum provided, offering growers an efficient and versatile solution for various plant growth stages.


The color of light emitted by red-blue LED lights appears pink or purple, whereas full-spectrum grow lights produce a white light similar to sunlight. This distinction in color is crucial for optimizing plant growth and development in indoor environments.

4、Light intensity

Full spectrum LED grow lights outshine red-blue lights in terms of light quantity, ensuring plants receive a broader range of wavelengths for optimal photosynthesis and growth. This enhanced light spectrum contributes to healthier and more vigorous plant development in indoor cultivation setups.

5、Indoor planting

Growers may find white light more comfortable for indoor cultivation as opposed to the pink and purple hues of red-blue plant grow lights, which can potentially cause dizziness, nausea, and physical discomfort in prolonged exposure. Choosing a soothing spectrum enhances the indoor growing experience.

What is the difference between the full spectrum LED grow lights and HPS grow lights?


The led full spectrum grow light offers an abundance of blue light, surpassing the HPS growth lights. This increased blue light enhances plant photosynthesis, promoting healthier growth, improved flowering, and overall superior crop yield in comparison to traditional HPS lights.


Full spectrum grow lights come at a premium cost compared to HPS grow lights due to advanced technology and increased energy efficiency. Despite the initial investment, the long-term benefits in plant growth and energy savings justify the higher price.

3、The cost of maintenance

The later maintenance cost of full spectrum plant growth lights is relatively lower than that of HPS growth light while the purchase cost of full spectrum plant growth lights is higher than that of HPS growth light.

  • The service life of full spectrum growth light is longer, which can be used for 50000 hours. The ballast of HPS grow light is aging fast, which means that the lifetime of HPS growth light is not as long as that of full spectrum grow light.

  • It does not need to change the bulb frequently for the full spectrum LED grow light, while the bulb of HPS growth lights needs to be changed half a year, this requires additional labor and material cost.

  • the cooling device is usually needed to dissipate heat produced by the plant grow light. The full spectrum LED grow light generates less heat than the HPS grow light. It can cut down the additional electricity cost when using the full spectrum LED grow light.


Full spectrum LED grow lights emit a white light resembling natural sunlight, providing a balanced spectrum for optimal plant growth. In contrast, HPS grow lights emit a yellow light, lacking the comprehensive spectrum, which can affect plant development and yield.

5、Amount of heat

While delivering equivalent light intensity, full spectrum led grow lights for indoor plants generate less heat compared to HPS grow lights. This heat reduction not only promotes a more favorable growing environment but also contributes to energy efficiency and lowers the overall temperature in the cultivation space.

6、Energy efficiency

The full spectrum led grow lights for indoor plants prove more energy-efficient than HPS plant grow lights, consuming less power while providing comparable or superior light output. This results in reduced electricity costs and a more sustainable and cost-effective solution for indoor cultivation.

7、Mounting Height

The full spectrum grow light can be hanged more closer to the plants, while the HPS must be far away from the plants, otherwise it will burn to death.

There is no absolute conclusion about which kind of light is better.

The three types of grow lights have their own advantages and disadvantages.

It needs to be selected according to the specific plant;s species.

For example:

If we need to grow sun-requiring plants ,both HPS grow lights and full spectrum grow lights can be chosen, but full spectrum LED grow lights is preferred because it imitates the sunlight and saves more energy .

3、Full Spectrum LED Grow Lights Myths

Many light manufacturers enthusiastically emphasize on the benefits of full-spectrum LED grow lights such as improving plant growth, achieving higher energy efficiency, and better replacement of sunlight. Are all of what they claim reliable?

According to some experiences and research, full spectrum LED grow lights do have some benefits in some cases.

  • Improve plant growth

"In the thesis 'Effects of Different LED Light Sources on the Growth and Development of Tomato Seedlings,' red light, full-spectrum white light, and fluorescent light (CK) are exposed to the tomato seedlings to study the effects of different light sources on the growth of tomato seedlings. The results showed that the tomato seedlings exposed to full-spectrum white grow light had a darker leaf color, shorter and stronger bodies, well-developed roots, and a higher seeding index."

  • Provide more lights than non-full-spectrum light

Full-spectrum LED grow lights do provide more lights than non-full-spectrum growth lights, such as green light, infrared light, and ultraviolet light. These lights also affect plant growth, even if they are not as important as blue light and red light.

  1. Green light can penetrate the crown of a plant better than the other wavelengths of light.

  2. The infrared light can induce plants to avoid shadows, make them stretch out, and induce early flowering.

  3. Ultraviolet light can induce protective compounds in plants.

However, manufacturers selling full-spectrum LED grow lights can make greater profits. Some manufacturers and brands claim that their lights are 'full-spectrum,' even when they are not.

When choosing a full spectrum LED grow light, it is advisable to carefully check the spectrum, CRI, and CT provided by the seller. This is because we may not be able to discern the differences from the color appearance of the lights alone. If possible, consider taking the purchased light to professional institutions to obtain the exact spectral composition, CRI, and CT of the full spectrum light.

If you are looking for a best grow light that works best for planting cannabis, Photonican  Aurora 2000 LED Grow Light will be your the best choice.

We believe cannabis needs a quality spectrum that imitates the spectrum of sun to deliver quality yields. Photonican Aurora 2000 LED Grow Light has a full spectrum with invisible light( red, orange, yellow, green, green, blue, and violet in turn)and small amount of  invisible light( near infrared light and ultraviolet A light)

What's more, Photonican's spectrum provides at least 30% more red spectrum output than most similar LED grow lights on the market, which can boost yields and increase cycles in a year.

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