What is Spectrum?

The spectrum is a continuous range of electromagnetic radiation waves. It ranges from the longest radio waves to the shortest X-rays and gamma rays.


Electromagnetic spectrum and wavelength


What is The Light Spectrum

Light Spectrum: After the polychromatic light is split by a dispersion system (such as a prism, grating), the dispersed monochromatic light is arranged in order according to the wavelength (or frequency). The full name is the optical spectrum. The optical spectrum is a small portion of the electromagnetic spectrum.


The part of the spectrum visible to the human eye. Electromagnetic radiation in this wavelength range is called visible light. The visible light wavelength range is about 380nm to 750nm.


Biology and spectrum

180~280nm UVC: These wavelength are lethal to bacteria, virus and other microorganisms.

280~315nm UVB: This component has deleterious effects in many biological systems

315~400nm UVA: Inhibit mold growth and fungal development, Increase the amounts of THC, CBD, and terpene production in cannabis plants

380~750nm The range of the electromagnetic spectrum that we are able to see as colour

700nm~1mm Infrared: above 750nm Invisible to the human eye but can be felt as heat.



What is PAR (photosynthetically available radiation)?


Photosynthetically active radiation (McCree curve)

Photosynthetically active radiation (PAR) is light of wavelengths 400-700 nm and is the portion of the light spectrum utilised by plants for photosynthesis. Photosynthetic photon flux density (PPFD) is defined as the photon flux density of PAR.

However, PAR from 400nm-700nm doesn’t actually encompass all the usable wavelengths, new research has demonstrated that far-red 730nm light is Photosynthetically Active when combined with shorter wavelength light.

UVA can increase the THC content.


Absorption wavelengths of plant photosensitive




Photosynthesis Absorption and wavelength


Chlorophyll A & B – photosynthesis

C​arotenoids – photosynthesis, photo-protection

Crypto​chromes – endogenous rhythms, organ orientation, stem elongation, stomatal opening, germination leaf expansion, root growth, phototropism, flowering induction

Photo​tropins – phototropism, stomatal opening, chloroplast movement, leaf expansion

Red & Far-Red Phytochrome – neighbour perception, expansion, shade avoidance, stem elongation, seed germination, flowering induction


Blue light (400-500nm)

Blue light Trigger morphological responses related to photoreceptor cryptochrome and phytochrome.

Blue light will inhibit the upward growth of crops. Multi blue full spectrum is suitable for use in the seedling stage of plants and is conducive to the growth of plant roots and stems.

Blue light can also trigger chlorophyll accumulation and leaf expansion. Blue light can increase carotenoids and anthocyanins, which is conducive to crop coloring.


Green light (500-600nm):

Green light does not seem to play a role in photosynthesis. In fact, the photosynthetic efficiency of green light is similar to that of red light, but in the deep layer of leaves, the photosynthetic efficiency is higher than that of blue light, because green light can penetrate leaves, so that lower leaves can carry out photosynthesis.

More importantly, the white light generated by red, green and blue light makes the working environment more comfortable, which is also in line with one of the 6 elements of plant grow light (friendly to human body)


Red light (600-700nm)

Red light is the most effective absorption spectrum in photosynthesis, which is conducive to the synthesis of sugars and VC in fruits and vegetables. Red light is suitable for flowering and seed formation


UVA radiation is important in inducing production of phenolics, anthocyanins (coloration), antioxidants and vitamins that inhibit mold growth.

For photosynthesis, the most effective and efficient light is in the red region (600-700 nm), followed by blue (400-500 nm), and then green (500-600 nm). These blue, green and red wavelengths (400-700 nm) are considered to have photosynthetic activity and are used by plants.


About tunable spectrum:

This is usually achieved by using blue-rich light to promote vegetative growth and switching to a higher red light spectrum to induce flowering.


The following is our recommended application of adjustable spectrum for reference only:


Seedling stage, more blue light full spectrum


During the vegetative growth period, increase the red spectrum



Flowering stage, Add far red light