What are full spectrum LEDs and why should we care?
So, what’s all the hoopla over full spectrum led grow lights? Why don’t traditional grow bulbs come in full spectrum and why is full spectrum so important to your cannabis plants? We are going to answer all these questions in this article once and for all.
Full spectrum isn’t a scientific term, it doesn’t reflect any scientific measurement or phenomenon but rather is a general description of the light properties of a source. The visible band of spectral radiation is between 390 to 700 nm. This just means that the human eye responds to these specific ranges of light meaning your brain can see it. This does not refer to full spectrum light, but we’ll get into that a bit later. We will only be discussing indoor plant grows extensively. Plants grow incredibly well using a grow led.
Here are some of the terms you might hear related to a LED plant grow:
- spectrum growing lamp – standard grow lamp
- veg flowering – terms for the two states of your indoor plant grow.
- spectrum king – An off brand of Chinese Led Grow Lights
- veg and flower – terms for the two states of your indoor plant grow.
- lamp panel – another term used to describe and LED Grow Lamp
- veg bloom – terms for the two states of your indoor plant grow.
- hydroponic systems – grow systems that do not use soil
- double chips – generally two 5-watt chips are place together to create one beam
- double chip led grow lights generally two 5-watt chips are place together to create one beam
- 5w led – a standard LED Chip size
Plants produce energy by way of converting energy, C02 and H20 into sugar using photosynthesis. Evolution has ensured that cannabis plants benefit most from the radiation bands produced by the sun. For grow lights for indoor grows we must pick a light source that mimics closest the suns radiation energy. By doing this you can produce the same or better-quality cannabis plants indoors because of the extra control over environment.
The following light sources are suitable for growing cannabis indoors, but some sources are better than others because of the amount of radiation they produce and the spectrum of light they produce. There is no difference in a light for hydroponics or for a soil grow.
- LED grow lights
- HID grow lights
- High-pressure sodium (HPS)
- Metal halide (MH) grow lights
- Fluorescent (CFL) grow lights
What are Chlorophyll and Cartenoids and What Do They Do?
These two pigments are the key to photosynthesis and can be found in chloroplasts which are found in the stems and leaves of your cannabis plants. Chlorophyll which is the green pigment we see in leaves converts light energy into sugar to feed the plant. The green chlorophyll absorbs red and blue light waves and reflects the green wavelengths which make plants appear to be green to our eyes.
There are two distinct chlorophyll molecules aptly named chlorophyll A and chlorophyll B.
Chlorophyll A is the more significant molecule involved in photosynthesis and passes energized electrons onto the sugar-producing molecules. This form of chlorophyll reacts to the light spectrum between 420 nm and 660 nm.
Chlorophyll B reacts to spectral radiation between 460 nm and 630nm. Evolution has ensured that cannabis plants can convert almost all the sun’s energy into sugar through other colored pigments. These additional pigments can’t convert energy to sugar directly, instead, they pass their energy on to chlorophyll receptors which carry out that function. The next most abundant pigment comes from Beta-Carotene which absorbs blue light other pigments pick up yellow, orange and red spectrum. Though these other pigments may be less in number they are just important because they control plant hormone cycles which control growth cycles and other non-photosynthetic functions.
First Generation Two-Band Lamps
To the human eye, the light spectrum between 390 nm to 700 nm is visible. Your cannabis plants respond to a wider spectrum of light between 390nm and 700nm+. This means that besides the spectrums visible to us a full spectrum light contains light in the UV and IR ranges as well. To our eyes, yellow and green appear brightest but for plants red and blue are the brightest. This means that the greatest amount of photosynthesis takes place in this region also known by the measurement PAR or Photosynthetically Active Radiation.
The Knowledge Center: We dive into the details
PAR is Just a Measurement
PAR isn’t anything to do with golf, in this case, it simply refers to the radiation emitted from a source of light that is used by a plant for growth.
Early LED Grow Lights relied on two narrow bands of light at 630 nm (red) and 460nm (blue). This worked but only activated two of the four types of chlorophyll receptors in particular chlorophyll A. These early lights were not efficient at growing cannabis, they worked but you were better off growing with an HID (high-intensity discharge).
The early LED grow lights had two major limitations. The LEDs were able to produce a weak 10-15 lumens per watt while new models of LED grow lights run at the 70-80 lumens per watt. By the way lumens per watt is a measurement of how much energy is converted to light or its efficiency coefficient.
These early LEDs also caused bleaching due to their narrow beam of focus around 30 degrees. As well not all the chlorophyll A receptors are targeted by the spectrum of provided light.
Modern LEDs and we will consider any LED grow light built after 2016 a modern LED grow light target up to 16 bands of light spectrum while the average light produces 8 bands. With the extra light spectrums light between deep-red (660nm) and royal blue (430nm). Additionally, IR and UV, as well as white LED, are added to fill in the spectrums that cannabis plants vegetation and flowering depend on.
Full Spectrum LED lights
The term full spectrum isn’t a scientific term or measurement but rather refers to how manufacturers describe their light spectrum coverage. You might notice some brands of LED grow lights advertise 7 band, 9 band or even 12 band full spectrum. Here is an example of a common 9-band setup:
- Yellow – 580nm
- Orange – 610nm
- Red – 630nm
- Deep red – 660nm
- Blue – 460nm
- Royal blue – 430nm
- UV – 410nm
- Infrared (IR) – 730nm
- White – 14,000K
Many manufacturers such as Black Dog, Apollo and a list of Chinese UFO style and panel lamps sold on eBay and on AlibabaExpress.com would be like this. These lamps are better than 2 band styles but most lamps in this category will lack the correct color mixing for your cannabis plants. These LED panels tend to have a light that spikes in specific wavelengths.
New Generation LED Grow Lights (light for indoor plants)
The newest LED grow Lights are generally cob led grow light style which is short for chip on board. This simply means that the LEDs use many colored emitters on one chip which takes care of color missing issues. The newest LED grow lights also provide the best cost to energy created ration available. LED grow lights have become so efficient that many newer grow panels don’t require fans to cool them.
What Does “Full Spectrum” Mean? It Means your vegetable garden just went on steroids!
Well generally if a manufacturer calls their products full spectrum they usually mean that their product outputs a wide and powerful light across most of the PAR range. Full Spectrum led grow lights as a term is only as good as the manufacturer claiming it. There are no certification or standard requirements to call your LED grow light full spectrum.
In reality, quality LED grow light manufacturers are moving away from traditional bands and developing the ability to provide the widest possible spectrum. Any company that is doing research and development is moving away from pink/purple lighting that we now recognize as LED grow light and replacing their LED chips with white chips.
These white chips all start out producing the same light band and power. These lights rely on fancy techniques of coating the LEDs with phosphor. This coating by way of thickness produces variations in color temperature of the LED. This new solution provides much wider bands of usable light which of course benefits your cannabis plants.
Is there a Best Spectrum?
In a perfect world, a LED grow light would replicate the spectrum that our sun produces while allowing us to adjust the intensity of the light to the exact needs of the cannabis plant. This would truly be called full spectrum grow lights. Natural sunlight is very evenly spread and its wavelengths peak in the PAR spectrum.
Cannabis plants are able to put to use light wavelengths outside of the PAR spectrum, but the light is generally too powerful or too weak to support primary photosynthesis.
So what spectrum would plants ideally benefit from and how much of each color do your cannabis plants require to flourish? Well as it might we do have a scientific answer which figured this out for us by a scientist named McCree in 1972. He figured out and published a chart that displays visually the required bands of light that support plant growth.
Major Factors to Consider for Your Cannabis or Vegetable Garden
Now that we understand the science supporting full spectrum LED grow lights here are the factors that should be considered when you are buying a Full Spectrum Led Grow Light.
LED grow lights are coming down in price quickly but beware, there are a lot of cheap LED grow lights on the market that are just a complete waste of your money. You need to stay away from no-name Chinese grow panels as they have zero quality control and have not invested in any technology development.
You should only be looking at reputable grow light companies. The cost of a true full spectrum LED grow light with enough intensity to grow cannabis well is going to cost you more than a traditional HPS or HID setup. I know that’s bad news for your pocketbook, but you do get the extra investment back on the back end of owning one of these lights.
Unlike traditional incandescent light bulbs which are a lifespan of about 15000 hours, LED Grow Lights have a lifespan of over 50,000 hours. LED panel also use close to 50% less electricity to generate their light. This means that you will be saving money on each grow with an LED grow light when compared to a traditional HID light.
Traditional HID and CFL setups are really not ideal for a grow area due to their bulky size, many HIDs have a venting system and fans involved to help reduce heat generated by the light. All the heat, by the way, is wasted energy that you are paying for.
LED grow light fixtures are generally much smaller because they don’t contain ballasts or large venting fans. The standard growing distance for an LED panel is much less than that of an HID light as well which opens up more height in your grow area for your plant to grow into.
Light and heat, you can’t have one without the other, efficiency such as with LED grow panels produce more usable power and less heat than traditional lights but they sure as heck still produce some heat. The heat that lights produce are the single greatest factor for the ambient temperature of your grow to by high which of course requires more intervention to prevent. Just know that this issue is greatly reduced with LED grow lights as they produce about 60% less heat.