Buying LED Grow Lights: Full Spectrum or Red & Blue

Buying LED Grow Lights: Full Spectrum or Red & Blue

The growth of cannabis in the indoor condition is highly adopted these days in many areas of the world. The people who did not have open fields used indoor growth setups.

In some countries, cannabis growth is not legally allowed in open fields. Hence people have to use grow lights to go indoors.

The best possible solution for indoor plants is growing them through grow tents. In grow tents, the provision of light is mainly made by using LED grow lights.

Many other light options are available in the market, but the most suitable or adopted method is LED grow lights.

The usage of LED grow lights are dependent mainly on the watts necessary for the plants. The one important factor most indoor cannabis growers did not notice is that light can have many wavelengths.

It is important to understand which light color is beneficial for the cannabis plants and which one is not. There are two types of lights commonly used in cannabis growth. To decide which one is best, you have to understand their characteristics.

In the article, we provide you with every detail about LED grow lights, their different light characteristic and information regarding essential wavelengths to use in plant growth.


What is Full Spectrum LED Grow Light?

LED grow lights from cultiuana


The surprising thing for everyone is that there is nothing true about the full spectrum of grow lights. The full spectrum of light is only one in nature: sunlight.

The full spectrum LED grow lights are called such because they are very close to sunlight. The electromagnetic spectrum covering infrared to ultraviolet wavelengths of light and is helpful for plant growth is called Full Spectrum LED grow light.

Full spectrum is a marketing term used to explain these lights because they are identical to sunlight.

The term previously explained only the sunlight, but with the advancement in modern sciences and its application, scientists adopted the term Full Spectrum to the light very close to sunlight and used it to grow plants.

But, they are not fully optimized like the sunlight and do not even include the entire solar spectrum. Full spectrum LED grow lights have one other difference from sunlight, and that is their less dynamic nature as compared to sunlight.

White light, similar to sunlight, is achievable by using full spectrum grow lights, but it does not mean every white light is LED full spectrum light.

As opposed to the usual LED grow light approach of blue and red monochromatic LEDs, full-spectrum growth lights will generally use a phosphor coating. Phosphor coatings are helpful in the full spectrum of grow lights because they transform light from a single restricted wavelength range, e.g., 460 nm blue, to a broad range of longer wavelength spectrum, e.g., 600 - 700 nm red.

Considerably more extensive coverage in the visible light spectrum can be accomplished by treating a blue LED with a mixture of greenish, yellow, or red phosphors.

Because the phosphors emit light at a wide range of wavelengths, the end effect is a well-balanced blend of colors that produce white light. A straightforward technique is to calculate its color rendering index (CRI).

This is important since it shows how close it is natural sunshine. A higher CRI value implies that the light source is comparable to natural sunlight.

The wavelength of the light lies in the full spectrum region of grow light is 380 to 740 nanometers. A standard grow light employs a mixture of red and blue lights because they are primarily used in plant growth.

In photosynthesis, plants mostly need red and blue lights because they do not absorb green wavelengths but reflect it. The mixture of blue and red light gives a pinkish purple shade.

Some people might think that red and blue light are conventionally used in growing plants; then what is the need for full spectrum grow lights?

The explanation is that additional activities that affect plant growth and health are not only determined by the amount of photosynthesis that happens. The full spectrum of light ultimately leads to a higher quality crop, better aesthetics, and greater nutritional content.

It is hence adopted these days universally for the indoor growth of cannabis plants. It is undoubtedly more beneficial than the other methods. Speaking about the benefits, here are some of the benefits of full spectrum grow lights.

Benefits of Full Spectrum LED Grow Lights

Full Spectrum grow lights have many benefits compared to other light sources used in plant growth. 

  • Full Spectrum LED Grow lights beat the other lights in the efficiency
  • It has a longer life than simple grow lights
  • It produces less heat because of its even distribution of lights everywhere.
  • The power expenditure of Full Spectrum light is half of the other types of lights used.
  • The production of the plant is high as compared to other lights • It is cost-effective and easy to install for inside growth
  • Full Spectrum light is environment friendly
  • The plant production by using full spectrum grow lights is harm free
  • Full Spectrum grow light is safe for human beings

What is A Red/Blue Grow Light?


red and blue lights


Red and Blue grow lights are necessary for indoor plant production. It is the second best option after full spectrum grow lights. Blue light has a shorter wavelength while red has a longer wavelength.

Blue wavelength lies at less than 500 nm. On the other hand, red light has a greater wavelength and ranges from more than 600 to 700 nanometers. It is necessary to understand all the details of blue and red wavelengths, so that you can probably use them for better plant growth.

Blue light's influence on plants is closely tied to chlorophyll production. Plants that receive a lot of visible light will have healthy, strong stems and leaves. Red light is fundamental for plants blooming and producing fruit.

It is also required for germinating seeds, root development, and bulb development in young plants. While outside plants in full daylight will naturally receive both red and blue light, but interior plants may not. Even plants near a window may not receive enough of a specific color range.

Plants require blue and red lights equally for their proper growth. But, you must know that if your plant growth is slow in the early stages and the plant loses its green color daily, then there is a lack of blue lights in your light application.

On the other hand, red light is responsible for bringing plants to flower. Hence, if the flowers do not appear or appear late, then there must be an issue with the red light application of your plants. The PAR wavelength range is 400-700nm. Blue light is one extreme of the spectrum, and red is the other.

As we previously discussed, blue light plays an essential role in the vegetative phase. Blue encourages root development as well as solid plant growth.

When you spray your small plants with blue light, you are preparing them to support a large number of buds in the later phase of the plant.

On the other hand, red light is most effective during the flowering stage. A higher red intensity encourages a higher yield. Hence, Blue and Red lights are suitable for plant growth.

What is the difference between full-spectrum LEDs vs Red/Blue?


white and red and blue lights from cultiuana


Before discussing the difference between these light spectrums, you must know the importance of green color light in plant growth.

We usually avoid green color light by saying that plants do not use it. But this is partly true. In fact, green has a lot to do with photosynthesis.

We mostly think that plants reflect all green color wavelength lights, but in reality, plants reflect only a portion of it.

The remaining portion of the green wavelength is beneficial in maintaining the plants' chlorophyll level.

It also helps complete the photosynthesis procedure, which is plants' food making process.

There is a lot in common and a lot to differ in both these spectrums, but one thing is to guarantee that both are used in plant growth.

The Blue and Red spectrum showed a pinkish purple color, and the full spectrum mostly showed white light.

The comparison between them can give us better detail on which is more effective.

  • Full-spectrum lights have a broader wavelength range than Red-Blue Grow Lights, which means they can assist plants in absorbing additional light energy and develop at a faster rate.
  • Full-spectrum LEDs produce less heat than standard incandescent light bulbs, which may be beneficial to cannabis farmers concerned about high temperatures harming the taste or yield potential of their buds.
  • For eight hours, red-blue grow lights emit lower brightness than full spectrum lighting, which is why they are frequently used as supplementary lighting rather than as the major light source for plants
  • Full-spectrum LED grow lights do not generate heat exceeding body temperature, which is beneficial if you are growing marijuana in a cold environment.
  • Full-spectrum lights distribute heat more evenly across grow tents or plants, which can increase their general health and development rate. Because red-blue light sources may cause spots on plants, choosing a broad spectrum source is frequently safer for your plants.
  • Red-Blue Grow Lights are typically less expensive than Full-Spectrum lights; however, they may not deliver the same light intensity. If you want significant outputs from your cannabis plants, this can be a disadvantage.
  • Full-Spectrum LED Grow Lights can be used with either HPS or MH bulbs, allowing you to tailor the lighting to your individual requirements.
  • Full spectrum LEDs have a longer lifespan than red-blue LEDs. They release more blue radiation than red light, which may have an adverse effect on plant development and growth.
  • Full spectrum LED grow lights are more costly than Red-Blue LEDs, but they usually come with an extended warranty and better company support


An Ideal or Optimum Spectrum for Plant Growth




Your application and the objectives you wish to attain will determine the optimum growth spectrum. As a result, an optimal spectrum does not exist because different species and varieties respond differently to different wavelengths.

We've seen this in crops like cannabis and roses, where planting various species under similar wavelengths and climatic conditions resulted in dramatically diverse growth rates.

Setting up a trial area to evaluate how different species behave is the most remarkable approach to determine precisely what your plant will do in these light applications.

Finally, when selecting a light for your garden, be sure that the light source delivers adequate brightness for the plants you grow.

Because different light spectrums can influence growth characteristics, you must understand which growth features are essential to you.

A customized light spectrum is not always required because most farmers seek higher yields and quality.

Hence, it is proved from our discussion that no one can explain the ideal spectrum of plants. Every plant has a specific need for light wavelengths. Every stage of a plant has a particular need for some wavelengths.

You cannot apply all at once, and you cannot use only one at once. It is one of the most crucial options to choose from for indoor plant growth. The ideal nature of the light spectrum is sunlight, which has every wavelength of light.

So, plant growers must understand that the full spectrum grow lights are closer to sunlight than blue and red light wavelengths. So, we can say they are ideal for plant growth.



Indoor plant growers can use both types of LED grow light spectrums to grow their plants. Plants need more Blue in their vegetative phase.

They need more red in the flowering stage. In between these stages, they need a small number of other wavelengths. Green is also used in plant growth as it is an important constituent of chlorophyll.

So, which one is best for plant growth? Here is an answer to your question. Full spectrum grows lights are expensive compared to red/blue lights, but they are more durable and have high strength and age.

Their functionality and efficiency are more significant than the blue/red grow lights. Hence, Full Spectrum grow lights are more beneficial for indoor plant growth.