UV420 Plasma Grow Light

UV420 - A Unique UV Grow-Light
The UV420 - Ceravision's high output UV-A and UV-B grow light

The UV420 plasma grow-light offers a leap forward for grow-lighting. The 420 Watt unit delivers high levels of UV-B, UV-A and blue and can be adjusted to optimise output to suit a growing cycle.

The vital UV-A/UV-B is absorbed by greenhouse glass and is absent from PAR lights.  The UV420 delivers high energy 'blue-end' photons to complement the abundance of low energy ‘red-end’ photons from PAR lights.  Together they optimise output to improve flavour, form and colour.

The spectral range targets key pigments and photoreceptors. Crops grown under UV420 units produce higher levels of terpenes, essential oils and flavonoids; trials with medicinal cannabis show cannabinoids can be boosted by up to 40%.

Trials at the Bridge Farm Group on industrial hemp and other herbs boosted oils, flavour and taste.  Watch Andrew Fuller, Technical Director at Bridge Farm interviewed by Shane Torpey of MIGRO here.

If you would like more information about this UV grow-light or to order units please email us here. 

Blue Light Benefits:  Short wavelength blue (400−495nm) has highest energy in visible light:

  • Absorbed by chlorophyll B to help counter the effects of shade
  • Increases stomatal opening for more CO2, improves water transpiration and nutrient uptake
  • Boosts production of secondary metabolites eg flavonoids and essential oils
  • Inhibits cell division and expansion to reduce leaf area and stem elongation and encourage compact plants
  • In strawberries, more fruit was produced with higher anthocyanin and sugar content; in basil, the oil content of leaves increased.

UV-A Benefits: The even shorter-wavelength UV-A (315-400nm) accounts for typically c.95% of the UV radiation reaching the Earth's surface.  Recent studies show that UV-A induces several photomorphogenic responses and important benefits:

  • Plants perceive and respond to UV-A to enhance growth and flowering 
  • Encourages epidermal flavonoids which have the potential to serve as antioxidants in some plant species 
  • Influences pollination and deters pests and diseases to reduce the need for chemicals
  • Use post-harvest to protect products from decay and increase shelf-life.

UV-B Benefits: Solar UV-B (280–315nm) is mostly absorbed by the ozone layer before reaching earth’s surface, but as the most energetic part of the spectrum it is crucial for plants:

  • Plants rarely display signs of UV-damage in their natural environment as they have evolved natural sunscreens
  • Perceived by the UVR8 photoreceptor, which regulates the expression of genes that provide UV protection in sunlight by increasing secondary metabolites eg essential oils, phenolics, terpenoids and antioxidants
  • Increases stomatal development to accelerate photosynthesis and create stronger, more compact plants with robust leaves
  • Small amounts of UV-B have large effects on morphology for minimal energy input during growth and post-harvest
  • Enhances the flavonoids that govern colour, taste and antioxidants to provide various health benefits: epidemiological studies link consumption of fruit/vegetables with lower risk of chronic diseases
  • Pre-and post-harvest, UV-B triggers glucosinolates induction that may prevent illnesses including cancer
  • Triggers resistance to fungal pathogens and pests that damage crops and reduce yield: trichomes and glycosides deter herbivores like aphids; and it works as well as fungicides eg for powdery mildew on strawberries, basil and roses.

Medicinal Cannabis Cultivation: Potent cannabis strains mainly originate within the equatorial regions around the globe and in high altitude regions where exposure to UV-A and UV-B is more intense.  It is not a surprise then that using UV grow-lights for indoor cannabis cultivation can boost  yields of cannabinoids eg Cannabigerol (CBG), Tetrahydrocannabinol (THC) and Cannabidiol (CBD):

  • UV-B drives plants to create cannabinoid 'sunscreens' with more and larger trichomes
  • Blue light improves stomatal opening for more CO2 and raises THC synthesis
  • UV-A and blue induces CBG accumulation in the flowers
  • UV-B deters fungal pathogens - Botrytis or Grey Mold -  common in cannabis cultivation. 
UV420 Total Light Delivered Over 2.0 m2
Other Plasma-56 Watts
CMH - 77 Watts
UV420 - 115 Watts



























The dose in the UV420 plasma grow-light consists of completely evaporated metal halides.  This removes potential degradation on the capsule's inner surfaces during operation and allows for lamp life in excess of 30,000 hours. Capsules in other plasma and metal halide lamps suffer from material stress caused through chemical reactivity of the metal halide liquid pool - the precursor to failure and reduced life.

UV420 Plasma Grow-light is a Perfect Complementary Grow-Light

This plasma grow-light is designed to complement PAR grow-lights - HPS, metal halide and LED lamps.  With a spectrum concentrated from 280 to 550nm, it delivers the UV-A and UV-B not transmitted through greenhouse glass and not available from these PAR lights.

  • HPS provides an efficient source at the red-end of the PAR region, but not much usable blue light and no UV-A or UV-B
  • Metal halide (MH), Ceramic metal halide (CMH) or Fluorescent lights provide some blue spectrum but they have little - if any - UV
  • LEDs have little if any useful levels of UV-A or UV-B.   
Photosynthetic Pigments, UVR8 Receptor & UV420 Spectrum with HPS Spectrum (Ceravision)

Adjustable UV Output

The quantity and wavelength of light reaching the crop can be modified according to the reflector glass selected (see charts below):

  1. Blue light and UV-A transmitting filter (white frame) - fitted in the unit: lots of blue light and little UV-A and UV-B; 
  2. Enhanced UV-B transmitting filter (red frame) - on the side of the unit: increased UV-A and UV-B; or
  3. Enhanced UV-A transmitting filter (blue frame) - purchased separately if required from your supplier.
UV420 Spectrum - Relative Light Quantity
UV420 Spectrum - Relative Light Quantity 250-400nm​ (exploded view)

UV420 Grow-light Complements PAR Grow-Light (eg HPS, MH and LEDs)

Plants always need lots of PAR for photosynthesis and growth, but scientists now know they need UV-B for quality and value.  Plants grown outdoors receive varying amounts of UV-A and UV-B depending on time of year, latitude and altitude. In greenhouses however, plants receive little UV-A and no UV-B from the sun as these are absorbed by the glass. Traditional grow lights offer lots of PAR but provide incomplete wavelengths for quality, with the result that plants have inferior nutritional values, flavours and colours.

The UV420 grow-light provides the 'missing' UV-B and UV-A all year round at whatever location.   In cannabis, tests show that UV-A and UV-B increase resin production by over 30% to boost concentrations of cannabinoids - Cannabidiol (CBD) and Tetrahydrocannabinol (THC) and Cannabigerol (CBG).

The chart below shows how the UV420 spectrum complements a typical HPS spectrum in respect of the absorption spectra for chlorophyll ‘a’ and ‘b’  and the activation range of the important UVR8 photoreceptor that initiates the plant stress response to UVB.

Good Reasons to Choose the UV420 Plasma Grow-Light

The UV420 plasma grow-light has a spectrum of 280 to 550 nm with UV-B that is now recognised as crucial for enhancing crop quality:

UV420 Grow-light Boosts CBD in Medicinal Cannabis
Ceravision's UV420 outputs high levels of UV-A and UV-B to boost cannabinoids in greenhouse medicinal cannabis cultivation
  • Improved rooting, germination, vegetative growth, flowering and resinous, high yield crops
  • Abundant trichome production and thus more terpenes, essential oils and flavonoids
  • Protection from molds, mildew and pests for reduced use of chemicals
  • Improved pollination from pollinators attracted by the UV now on the flowers
  • Low maintenance, low running costs and compatible with contactors and timers
  • Small light source, compact luminaire and minimal shadowing
  • Easily changed reflector with UV-B and UV-A options to suit growth stage
  • Low lamp degradation, 50,000hrs+ magnetron life and a tough, durable casing
  • Complements PAR grow-lights to deliver fuller spectrum
  • Perfect for high value crops eg powering cannabinoids and terpenes in cannabis
  • Post-harvest, it continues to boost secondary metabolites and extend shelf-life
  • Between crop cycles it can help sterilise surfaces to eliminate mold and bacteria.

Light Distribution


UV420 Cone Diagram

Technical Data

 Product  Ceravision UV420 UV Grow-light
 Manufacturer   Ceravision Lighting Ltd
 Power Consumption  420 Watts
 Mains Supply Voltage  110-240 Volts at A/C 50-60 Hz
 Weight  10 kg
 Dimensions  400 x 400 x 195mm
 Ambient Operating Temperature  0ºC  to 35ºC


For further information about the use of UV light equipment and to make sure that you have the relevant health and safety information to ensure safe use and compliance with your legal obligations please visit UV Light Technology Limited here.


The UV420 plasma grow light is CE marked having completed compliance testing by independent laboratories to all relevant international standards. 

If you would like more information about this UV grow-light or to order units please email us here.  

Further Information

Future Applications

Delivering flexible spectral outputs, Ceravision's HEP plasma lighting offers added-value and economic solutions in horticulture grow-lighting and other commercial applications.

HEP Plasma Lighting Technology

Ceravision’s HEP plasma grow-lights, with a UV spectrum providing UV-B, UV-A and blue herald a new scientific direction for horticulture lighting.

Intellectual Property

Ceravision maintains an extensive Intellectual Property (“IP”) portfolio comprising Patents, Trade Marks and Design Rights.

Featured News

Dec 2019: Mr Andrew Fuller of Bridge Farm, explains how incorporating Ceravision's UV grow-light in its industrial hemp cultivation boosted cannabinoids by 40% (see video).


Oct 2019: Ceravision presents its new horticulture UV grow-light to demonstrate the reliability and flexibility of its patented plasma lighting at the NIAB Industry Workshop on Advances in Grow-Lighting...


Sept 2019: Independent lab tests on harvested industrial hemp crop at Bridge Farm Group confirm that incorporating Ceravision's complementary UV grow-light boosted cannabinoids by 40%.