UV420 Plasma Grow Light

UV420 - A Unique UV Grow-Light
Ceravision's UV420 grow-light - a unique UV grow-light for improving nutritional and medicinal crop values adding value in hor

The UV420 plasma grow-light is a leap forward in horticulture grow-lighting. This 420 Watt UV grow-light delivers high levels of UV-B, UV-A and blue and can be adjusted to deliver the optimum output to suit a growing cycle. 

The spectral range targets important pigments and photoreceptors. Crops grown under UV420 grow-lights produce higher levels of terpenes, essential oils and flavonoids.  Trials with medicinal cannabis show cannabinoids are boosted by this UV grow-light.

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

Separately, different spectral regions provide benefits, but their combination from the UV420 alongside traditional PAR fixtures produces synergistic benefits.

Blue Light Benefits:  The relatively short wavelength of blue light (400−495 nm) means that it has the highest energy in visible light:

  • High energy blue is absorbed by chlorophyll B to help counter the effects of shade
  • Improves stomatal opening to better access CO2, improves water transpiration and nutrient uptake
  • Boosts biosynthesis production of secondary metabolites eg flavonoid concentrations 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 (315-400 nm) accounts for 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: The sun's UV-B (280–315 nm) is mostly absorbed by the ozone layer before reaching the earth’s surface, but as the most energetic part of the spectrum it has many effects on organisms:

  • 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; and 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 Production: Potent cannabis strains originate in high altitude regions exposed to much UV-B.  For indoor cannabis cultivation, yields of Cannabigorol (CBG), Tetrahydrocannabinol (THC) and Cannabidiol (CBD) can be boosted using UV grow-lights:

  • In response to UV-B, plants create cannabinoid sunscreens with more and larger trichomes
  • Blue light improves stomatal opening to better access the CO2 crucial in production, and raise THC synthesis
  • UV-A and blue may act synergistically to induce CBG accumulation in the flowers
  • UV-B is also effective against fungal pathogens eg Botrytis or Grey Mould, common in cannabis production. 
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 metal halides that are completely evaporated.  This removes any potential for degradation on the inner surfaces of the capsule during operation and allows for lamp life in excess of 25,000 hours. Other plasma technologies and metal halide lamps suffer from material stress of the capsule caused through chemical reactivity of the metal halide liquid pool which is a precursor to failure and reduced life (see diagram below).

UV420's Patented Dose Provides Extended Life and a 2-year (12,000 hrs) Warranty
 Metal Halide     
Other Plasma    
  Metal halide
  Chemical reactivity
  Material Stress
- UV-A
- UV-B
- Blue


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

The quantity and wavelength of light reaching the crop can be modified according to the reflector glass selected by the user:

      Standard Glass: lots of blue light and little UV-A and UV-B (black line in charts).
      Enhanced UV: increased UV-A and UV-B (red line in charts below).
      Enhanced UV+: maximum UV-A and UV-B (blue line in charts below).

UV420's Spectrum - Relative Light Quantity
HEP Plasma Grow-light spectrum illustrates the UV and blue missing from PAR Grow lights
UV420's Spectrum - Relative Light Quantity 260 to 400 nm​ (exploded view)
Spectrum of UV420 HEP grow-light shows the UV and blue light options offered by this UV grow-light.

The chart below shows how the UV420 spectrum complements a typical HPS spectrum in respect of the chlorophyll ‘A’ and ‘B’ and the UVR8 receptors.

Photosynthetic Pigments Photoreceptors & the UV420 Spectrum with an HPS Spectrum (Ceravision)
Ceravision's plasma grow light spectrum with UV and blue light complement PAR grow lights to activate Photoreceptors


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

Plants always need lots of PAR for growth but scientists now know that they need UV-B to give them 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 20% and deliver greater concentrations of cannabinoids - Cannabidiol (CBD) and Tetrahydrocannabinol (THC) and Cannabigerol (CBG):  

  • 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 also lack sufficient UV, essential for optimal plant growth and development.   

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:

UV Grow-Light Boosts CBD & THC in Medicinal Cannabis
Ceravision's UV420 UV grow-light boosts CBD and THC cannabinoids in medicinal cannabis
  • Improved rooting, germination, vegetative growth, flowering and more resinous, high yield crops
  • Abundant trichome production and thus more terpenes, essential oils and flavonoids
  • Protection from moulds, mildew and pests for reduced use of insecticides
  • Improved pollination from pollinators attracted by the UV now on the flowers
  • Low maintenance, low running costs and compatible with existing contactors and timers
  • Uniform distribution of 2.0sq.m at 2.0m hanging height for penetration in hi-wire crops
  • 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 HPS and LED grow-lights for growth and quality and crop value
  • Perfect for high value crops eg powering cannabinoids and terpenes in medicinal cannabis
  • Post-harvest, it continues to boost secondary metabolites and extend shelf-life
  • Between crop cycles it can help sterilise surfaces to eliminate mould and bacteria.

Light Distribution


Technical Data

 Product Name    Ceravision UV420W
 Manufacturer    Ceravision Lighting Limited
 Power Consumption    420 Watts
 Mains Supply Voltage    110-240 Volts at A/C 50-60 Hz
 Weight    10kg
 Dimensions    400 x 400 x 195mm
 Ambient Operating Temperature    0ºC  to 35ºC


To order the UV420 please click here.

For all commercial enquiries please click here.

Further Information

Future Applications

Offering 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

Ceravision is now a member of UV4Plants - the recently formed International Association for Plant UV Research


Ceravision delivering the first of its UV420 plasma UV-B and UV-A Grow-lights to The Greenhouse Effect


Ceravision's new UV420 plasma grow-light is shown at Autopot Summer Social 18th - 19th August 2018.