Indoor cultivation

Industrially Designed For Lasting Reliability

Grow-Ray LEDs surpass the output of traditional DE HPS lights in intensity, optimized spectrum, uniformity of high value PPFD (Photosynthetic Photon Flux Density) and longevity. Grow-Ray's modular construction permits future upgrades to tomorrow’s LEDs for a fraction of the cost of a new lighting system. Grow-Ray utilizes the newest​, high-output ceramic LEDs from Osram, a world leader in solid-state lighting.

Grow-Ray's passive heat management system is critical to maintaining the intensity and lifetime of its LEDs. In addition to CAD heat management modeling and field testing, Grow-Ray's fixtures produce the most powerful and uniform light available. Full spectrum provides better canopy penetration, utilizing the green spectrum to transport photosynthetic receptors in the red and blue range.

The Grow-Ray proprietary spectrum increases plant visibility and eliminates the eye strain that can result from working under HPS lights. A higher Color Rendering Index (CRI) helps the grower see potential problems at the canopy level with greater clarity than traditional HPS, HID and many LED fixtures.

Grow-Ray's patent pending passive thermal dissipation 

Higher Yields, Lower Cost of Production and Increased Plant Health

Warehouse applications can count on 25% to 40% energy savings, compared to an 1100W DE ​HPS​, wall plug to wall plug measurements. Lower HVAC costs, both installation and ongoing, accounts for an additional 20% to 40% energy savings. ​Much higher LED efficiencies translate to far less heat produced.

Grow-Ray lights are designed for professional, commercial horticultural applications, where production is pushed to the maximum. Passive thermal dissipation ensures efficient heat transfer from LEDs and drivers, avoiding the main cause of LED degradation and failure: heat overload. Grow-Ray LEDs are the highest quality available. They have a longer life, and produce reliable light intensity and quality over the long haul. The thermal map (​above) shows how efficiently Grow-Ray fixtures manage heat. Within a half inch of the light bar, the vast majority of heat is dissipated.

Grow-Ray Spectrum is Optimal for Mothers and Clones

Grow-Ray lights are designed for clones, seedlings, and early-stage plants, all the way to full flowering. For lower light applications, Grow-Ray lights can be programmed from full power to about 20% of full power with a smartphone app (Android only for now), or with an NFC accessory wand (not included) for a tablet, laptop or PC. 

Increase Yield and THC+Terpene Profile

Grow-Ray’s high output, modular four, six and eight-bar systems deliver the most uniform and intense lighting coverage available today. They are designed to be a superior 1:1 replacement of DE HPS fixtures. Grow-Ray luminaires deliver industry-leading PPFD (Photosynthetic Photon Flux Density) and efficacy numbers.  Grow-Ray also provides a unique, PhD-designed spectrum that increases both dry weight yield and THC/Terpene profiles. 


Plants perceive and adapt to their environmental surroundings for optimal growth and development. Illumination is the most powerful environmental stimulus for plant growth and plants have sophisticated sensing systems to monitor light quantity, quality, direction, and duration. Pigments and photoreceptors present on plants control plant photosynthetic and photomorphogenic processes.

The range of light that induces photosynthesis in plants is called Photosynthetically Active Radiation (PAR) and is defined as radiation over the spectral range of 400 to 700nm. Every absorbed photon regardless of its wavelength contributes equally to the photosynthetic process. The range of light that generates photomorphogenic processes ranges from 350 –750nm. These processes play a major role in the development of new tissues. The common unit of measurement for PAR is Photosynthetic Photon Flux Density (PPFD), measured in units of moles per square meter per second.

The plant’s metabolite production is also influenced by light spectrum. In addition to the primary metabolites of carbohydrates and amino‐acids, secondary metabolites are also influenced by light quality. Many secondary metabolites are key components for plant defensive mechanisms. They also contribute to odors, tastes and colors. At this point little is known about the manipulation of these secondary metabolites under artificial illumination systems. But it is known that restricting the light spectrum to a handful of wavelengths can be detrimental for plant development.

Using LED technology allows us to manipulate the light spectrum to trigger benefits in indoor production systems. With indoor lighting it is possible to create a custom designed spectrum to control plants’ development cycle and enhance biomass production.

Beyond the benefits offered by LED technology, Grow-Ray exploits the advantage of LEDs’ controllability. Using a combination of full spectrum emitters along with specially selected monochromatic LEDs, we can control a plant’s developmental pathways. This stimulates photomorphogenic processes, and maximizes biomass production through the photosynthetic process.

The ​Importance ​of a ​Full ​Spectrum

LED lighting companies generally provide red and blue LEDs because these wavelengths are efficiently absorbed by the plants main photosynthetic pigments, chlorophyll a and b (Fig A). They claim that blue and red LEDs alone are sufficient for horticultural applications. In reality, the situation is more complicated. Although chlorophylls are the main pigments found in higher plants, other pigments present on the leaves are also capable of absorbing light and in conjunction with chlorophylls, they extend the intact leaf’s absorption spectra that are capable of inducing photosynthesis.

Most importantly, the additional spectrum drives secondary metabolisms necessary for healthy plant development (Fig B). The spectrum allows a wide range of wavelengths to be absorbed. The "weakly" absorbed green-yellow wavelengths (500—600nm) bounce around the individual cells and are highly reflected by the water-air interfaces increasing their absorption inside the leaves. The higher penetration of green light compared to red and blue lights results in higher photosynthetic activity induced by green light in deeper layers of the leaf. The right balance of light quantity and quality promotes the highest energy efficiency while ensuring healthy plant development and maximum biomass production.

​Plant Development

In addition to chlorophyll and carotenoids for photosynthesis, plants use other photopigments for a wide variety of functions. Photomorphogenesis is the process of light‐mediated plant development. Plants sense light quantity, quality, direction and duration through a variety of photoreceptors which play a major role in developmental processes that generate new tissues (e.g. flowers and leaves). The most important photoreceptors ​in higher plants are the Phytochromes, Cryptochromes, and Phototrophins.

Phytochromes respond to the ratio of red (660 – 670nm) and far‐red (725 – 735nm) light. Phytochromes synthesize in the dark, convert to Pfr form and then move to the nucleus. Red light (660 nm) ​converts Pfr to biologically active Pfr form and far‐red light (730 nm) ​converts it back. Phytochromes influence several aspects of plant development including flowering, seed germination, de-etiolation, stem elongation, cell expansion, shade avoidance responses, and photoperiodism. Many of these events are related to alterations in plants hormone levels and growth regulators. These changes then cause alterations in plant morphology, physiology, development, and metabolism.

Cryptochromes and phototrophins respond mainly to blue light (380 – 470nm). Cryptochromes have a profound effect on seedling development and flowering. Among several plant growth responses, the most well know parameters influenced by cryptochromes are de‐etiolation and photoperiodic flowering control. Phototrophins contribute to plant form and function (e.g. chloroplast and leaf movement, stomatal opening) and unlike the general effects of cryptochromes, the plant responses guided by phototrophins are all ​related to optimizing photosynthesis.


The main pigments ​in indoor cultivated plants are the chlorophylls and carotenoids. The light intercepted by these pigments directly fuels the photosynthetic ​conversion of CO2 and water ​into biomass. To stimulate high biomass production without significantly affecting plant photomorphogenesis, light between 500 – 600nm can be used to charge the photosynthetic apparatus without stimulating the photoreceptors controlled by blue, red and far‐red wavelengths.

​Grow-Ray​ ​Spectrum

To achieve maximum biomass production with less energy consumption and ensure healthy plant development, Grow‐ Ray designed a custom light balance taking advantage of the latest LED technology. The specially formulated light balance regulates key plant developmental processes while maximizing photosynthesis. Using specially selected wavelengths at red (660nm), blue (450nm) and far‐red (730nm) combined with the full spectrum warm white LEDs, Grow-Ray ​luminaires can control plant flowering, photoperiod, leaf expansion, and plant shape while ensuring maximum biomass production.

Blue Light:

The selected blue LEDs in Grow-Ray lights affect leaf movement leading to flatter leaves which result in a more efficient surface for light absorption. It also encourages fast leaf expansion resulting in larger surfaces for light absorption and photosynthetic activity. Another very important attribute of the blue is related to stomatal activity regulation. Stomata are little apertures on the leaf surface which allow CO2 to move ​into the leaf. Higher concentrations of CO2 inside the leaf induce higher rates of carbon fixation and biomass production. Blue light induces stomata opening and allows for higher fluxes of CO2 inside the leaf.

Red Light

The main photosynthetic pigment present in plants, chlorophyll a, has its light absorption peak at 660nm (red spectrum). LEDs in this wavelength are also part of the Grow-Ray proprietary spectrum. Using red LEDs Grow‐Ray lights provide higher PAR values at lower energy consumption, maximizing​ energy use efficiency. Red light (together with far‐red light) also ​activates the photoreceptors responsible for flowering and photoperiod regulation, the phytochromes.

Far‐Red Light

Grow‐Ray is pioneering the use of far‐red emitters in commercial LED lights. Grow-Ray lights are equipped with supplemental far‐red LEDs that in conjunction with the red LEDs provide light at phytochrome absorption peaks. Controlling the duration and ratio of red/far‐red light makes it possible to control plant behavior to increase biomass production and accelerate plant growth.

  • Day Use Recommendation: The far‐red light provided by Grow‐Ray increases photosynthetic efficiency avoiding energy imbalances that can occur inside the photosynthetic apparatus under high‐light conditions. It allows the plants to convert more light energy into chemical energy which is required for biomass production and plant growth.
  • End of Day Recommendation: (Research project underway to provide scientific data) Cannabis plant flowering is regulated by the photoperiod process. The Cannabis photoperiod requires a minimum of 12 hours of darkness to flower. This process is controlled by the phytochrome photoreceptors. Grow‐Ray far‐red emitters can manipulate phytochrome response and trigger the plants into shorter dark periods and provide additional time for more flowering.

Warm White Light

All Grow‐Ray lights are equipped with white LEDs which deliver full spectrum light to ensure primary and secondary metabolite production. Grow‐Ray warm white LEDs are selected to match the required spectrum for optimal plant development at veg and flowering stages. The white lights provide a constant full spectrum light supply allowing for photomorphogenic processes to be controlled by individual blue, red and far‐red emitter manipulation without compromising photosynthetic activity. It ensures that the required light flux maintains optimum light energy conversion throughout the entire plant growth cycle.

  • Far‐Red Spectrum: The warm white LEDs used by Grow‐Ray deliver a small amount of far‐ red radiation which ensures healthy plant development and allows for phytochrome control using different ratios of simultaneous irradiation of red and far-red.
  • Green Spectrum: The amount of green light flux generated by the white LEDs used in Bloom‐Ray increases photosynthetic efficiency by deeper light penetration into the canopy and individual leaves. It is also useful in manipulating plant traits, counterbalancing the effects of blue‐light induced cryptochromes while not affecting blue‐light generated flux through phototrophins.
  • Blue Spectrum: The different amounts of blue light emitted by warm white LEDs in Grow‐Ray are carefully calculated to provide the right balance between wavelengths supplemented by the blue and red LEDs to induce specific desired plant responses at the different developmental stages.


Plants depend on light, or PAR (Photosynthetically Active Radiation) to photosynthesize and grow. PAR is the light from violet to near infrared, the spectral range between 400 to 700nm.  It includes the entire spectrum that we humans can see.  And while human eyes are most sensitive to green at 555nm, plants use every photon in this range regardless of its wavelength.  The entire spectral range contributes to the photosynthetic process.​ LED Horticultural lights are designed to produce different amounts of PAR. depending on wattage, optics, type and number of LEDs used. The common unit of measurement for PAR is Photosynthetic Photon Flux Density (PPFD), measured in units of moles per square meter per second.  

Plants can also use light from outside this range, from UV at 350nm to almost infrared at 750nm as part of the development of new tissues and compounds​.  This is called photomorphogenesis. ​​

Cannabis plants thrive in extremely bright, high PAR environments. They grow best with a bright, even light across the entire growing area.  Grow-Ray lights are computer designed and field tested to provide an efficient, extremely bright light that is distributed evenly across the full growing area.  This gives each plant the best opportunity to grow to its maximum, in the shortest possible time and produce the most flower and best results.

The charts below, show how bright and even Grow-Ray lights are compared to a typical HPS, 1100 Watt DE HPS.  Compare the PAR-matched, Grow-Ray TR8 (8-bar) LED to the HPS lights.  Even though the center numbers are intentionally matched for a fair comparison, the HPS light falls off dramatically at the edges of a standard 4 ft. x 4ft. square, compared to the Grow-Ray TR8.

Also important, is that due to the amount of heat generated, the HPS could never be used this close to a plant canopy without burning the plants below it, yet having insufficient PAR for the plants at the edge of this 4 ft. x 4ft. square.

Grow-Ray PAR Map