We have been upgrading many of our older, less efficient lights with LED lighting over the last few years, and plan to continue this transition in the years ahead.While the vast majority of our LED lighting performs very well in communities across the state, we have identified a small pocket of LED lights in our service that have turned from the standard white color to a deep purple color. The change in color is due to manufacturer defect that was recently identified and is being addressed. The defect causes the color of the light to gradually turn purple. The light otherwise continues to work. Duke Energy
Why Do LED Grow Lights Give You Purple Light?
Did you know that the purple light that comes from an LED grow light can be more beneficial to your plants than the white or orange glow you get from HPS and MH bulbs? The purple glow coming from LED lights is a combination of multiple wavelengths of light. This pinpointing of light is a major element of any LED light and their effectiveness on plants. It is important for growers to understand what causes this purple color and how it helps plants grow. That’s why we’re going to explain what that purple glow really is and why you want it in your grow room.
LED lights are made up of all kinds of wavelength combinations, and those combinations will create the light you give your plants. There’s not just one wavelength of any given set of colors, though. LED’s pinpoint specific wavelengths of light that benefit your plant and try their best to avoid offering wavelengths they don’t.
LED Light Wavelengths
The combination of wavelengths LED grow lights offer is what gives us the light we see. Each wavelength of light has a nanometer or “nm” range and LED grow light manufacturers choose specific wavelengths to target growth. Here’s what those color ranges look like:
- Blue light wavelengths are between 450 and 495 nm.
- Red light wavelengths are between 620 and 750 nm.
- Ultraviolet wavelengths are between 100 and 450nm. There are three types of UV wavelengths, two of which are used in the grow room: UV-A and UV-B.
- UV-C: 100 to 290 nm.
- UV-B: 290 to 320 nm.
- UV-A: 320 to 400 nm.
- Infrared wavelengths are between 700 and 1050 nm.
The purple color emitted by LED lights is caused by the combination of blue and red wavelengths of light that make up most LEDs. Studies show that these two wavelengths are critical in plant development, which is why manufacturers use multiple red and blue wavelengths in their grow lights.
Chlorophyll, the green pigment found in plants, absorbs and reacts to these blue and red wavelengths in order to perform photosynthesis — or to help them grow. What those specific wavelengths do for the plant once they’re absorbed, however, is vastly different.
Blue Light Wavelengths
Blue light wavelengths promote plant health by regulating growth. Plants exposed mostly to blue light tend to grow shorter and thicker, with shorter stems.
The leaves of these plants are a darker green color, and they’re much larger in size than those of plants that don’t get enough blue light.
Red Light Wavelengths
Red light wavelengths are equally beneficial to plant growth. Like blue light wavelengths, red light helps regulate growth. Typically, plants exposed to more red light grow taller with longer stems.
Red light wavelengths are also responsible for increasing the rate of photosynthesis in plants. It’s through a red light that plants are able to obtain the most energy.
Blue and Red Light Wavelengths Combined
Individually, these wavelengths stimulate different growth patterns. Blue light helps a plant’s growth, while red light helps with blooming and photosynthesis. When you combine them in LED grow lights they give your plants the light they need to stimulate all patterns of growth at the same time, which is exactly what your plants need to grow.
The combination of these two lights is also important because it allows the plants to follow a circadian rhythm. This means the plants will pretty much know when to perk up and when to rest, just as they would if they were outdoors feeding off the sun’s energy.
Together, blue and red light wavelengths provide the equivalent of a day-and-night cycle for plants. Because these plants would be grown indoors and aren’t exposed to actual sunlight, blue and red wavelengths remedy this.
The Benefits of Purple Light
Now that we know why specific wavelengths of light are used in an LED light, let’s talk about why that purple light is so beneficial to your plants.
HIDs shower plants with every wavelength possible, but purple LED lights isolate the specific blue and red wavelengths of light that benefit your plant. This is great for plants because it provides exactly what the plants need to grow and thrive, and it avoids giving them excess light that they’ll waste.
The ratio of red to blue diodes in a grow light will also benefit your plants. Whether you have more red than blue or more blue than red, you’ll get a lighter or darker shade of purple. Each shade has its own benefits, so you’ll want to find the right combination for your grow room.
- If you wanted better growth for taller plants, more blue wavelengths would be ideal, giving you a deeper purple look.
- For more leaves and better buds, you’ll need more red wavelengths, giving you a richer magenta glow.
- The addition of white or light-colored diodes will give you a pink/purple hue that encompasses wavelengths not usually found in other LED lights.
Best Purple LED Grow Light Brands
LED grow lights that offer purple lighting can drastically improve the way you grow your plants indoors. You can capitalize on the benefits of purple LED lights with various types of technology. Here, we’ll look at the different ways Advance Spectrum Max, California Light Works, and Kind LED give you their own blends of purple light:
LED light panels from Advance Spectrum Max provide a magenta/pink light. This shows that it offers a wide spectrum of light, ensuring that your plants get the correct wavelengths of light they need for vigorous growth throughout an entire grow cycle.
Aside from the multiple blue and red light wavelengths, Advance Spectrum Max LEDs like the S900 Advance Spectrum MAX LED Grow Light Panel also include an isolated infrared diode. This IR diode is great for quality resin production, which gives you richer flavors and scents.
California Light Works LED lights are great for regulating the amount and type of light your plants receive. Not all plants need the same ratio of blue to red light as others, so it’s helpful to be able to control how much of which wavelength your plants get.
The California Light Works SolarSystem 1100 LED Grow Light , for example, allows you to change the intensity of the blue, red, and purple wavelengths to dial in the specific lighting your plants need. While the spectrum range may be limited, they still offer what your plants need for vegging and flowering growth.
While not programmable, Kind LED grow lights are some of the most powerful LEDs on the market with one of the widest spectrum ranges. The Kind LED K5 Series XL1000 WIFI Indoor LED Grow Light , for example, uses a 12-band spectrum that implements ultraviolet (320 nm) and infrared wavelengths.
You’ll get everything you need out of a Kind LED light, though at a much higher price point than Advance Spectrum Max.
Why are some streetlights turning purple across Central Florida?
ORLANDO, Fla. – By now, you’ve probably spotted at least one streetlight turning a blueish-purple hue while walking or driving in the evening.
No, they’re not meant to be that color. While the lights still work as their intended purpose, there is a manufacturer defect that was recently identified, according to Duke Energy and Acuity Brands, the maker of the lights.
The effect occurred in a small percentage of American Electric Lighting fixtures with components that have not been sold for several years, according to a news release from Acuity. Acuity said it is due to a “spectral shift caused by phosphor displacement” usually seen years after installation.
“The light output is in no way harmful or unsafe. As always, we stand behind the quality of our products, and we have been proactively working with customers who have experienced the issue to address any concerns,” Acuity said.
Street lights that have turned purple illuminate N John Young Parkway in Orlando. (Copyright 2022 by WKMG ClickOrlando – All rights reserved.)
The Florida Department of Transportation said they are working with the manufacturer on the replacement of the lights, an issue they said is “being experienced not just here in Florida, but nationwide.”
The department also said while the lights are not the “desired color,” they provide intended safety benefits.
Duke Energy said they believe that the issue affects around 2,000 lights in their service territory in Florida.
We have been upgrading many of our older, less efficient lights with LED lighting over the last few years, and plan to continue this transition in the years ahead.
While the vast majority of our LED lighting performs very well in communities across the state, we have identified a small pocket of LED lights in our service that have turned from the standard white color to a deep purple color. The change in color is due to manufacturer defect that was recently identified and is being addressed. The defect causes the color of the light to gradually turn purple. The light otherwise continues to work.
Duke Energy
Duke Energy is replacing the lights as they are identified and said that once the affected light is reported that the light is typically repaired within a few days.
A spokesperson with Duke Energy said residents can request a street light repair by visiting their online street light repair tool.
Florida Power & Light said in a statement that customers can report streetlights displaying purple color by calling 1-800-4-OUTAGE.
We are aware that some LED streetlights are emitting a purple hue rather than the standard white light. Most importantly, these streetlights are safe and will not impact visibility. The purple hue is the result of a manufacturer defect and is impacting streetlights nationwide. We are working with the manufacturer to replace the affected lights as the required parts become available.
We apologize for any inconvenience and appreciate our customers’ patience as we work to correct this issue. FPL remains committed to continuously improving the service we provide our customers.
Florida Power & Light
Street lights that have turned purple illuminate N John Young Parkway in Orlando. (Copyright 2022 by WKMG ClickOrlando – All rights reserved.)
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Copyright 2023 by WKMG ClickOrlando – All rights reserved.
One Street Light Company to Rule Them All
After doing some digging, I found the initial explanation. Adam Rogers writing for Business Insider documents how one firm, Acuity, dominates the Solid State Lighting (SSL) market. SSL systems are systems which incorporate LED light in a particular way which is often considered advantageous for things like street lamps. Rogers says, “every city with purple lights that responded to my queries or has public records on the matter bought its LED lights from Acuity.”
So what was the issue? Well, Rogers talked to a representative from the City of Vancouver who says the cause is ultimately an issue with a defect unique to LED lighting. “There’s a laminate on the fixture that gives it its white color. As that laminate began to degrade, it caused the color tint to change toward purple.”
In one sense, this is our answer. A company seems to have had a manufacturing defect which is causing a new technology to glitch leading to purple roadways.
But this explanation falls short of answering an important question: why does one firm have so much effect on the lighting of the US (and Canada)?
Acuity was the largest manufacturer of lighting by market share in 2017 when the bad bulbs began to be created, according to research by Rogers.
It’s unclear how much Acuity dominates access to municipal markets based on the data, but the widespread presence of this defect suggests it has a decent amount of influence as a contractor for government at local and state levels.
Why is this the case? Well, the market for government lighting is a winner-take-all discussion. Street lights tend to not be purchased individually. Rather, governments at various levels accept bids for companies to create products on a large scale.
So say a city government wants to update its old street lights with new LED technology. It’s not as if agents shop at the discount street light store. They solicit companies who will provide the street lights, and the winner gets the whole project.
This sort of environment creates a scenario where a few winners begin to dominate the market, and smaller companies simply can’t compete for these larger projects.
Compare this to your own light bulb selection criteria. Do you select one brand of light bulb to light your entire house? Most people don’t. Instead myself, and many others, buy light bulbs one pack at a time based on who gives us the best deal.
This doesn’t mean a single company will dominate all lighting. Competition is more robust than that. But government contracting does lead to markets which are likely more concentrated than they would be if not for the contracting.
Without contracting, perhaps individuals or neighborhoods would work with private companies to provide lighting they are willing to pay for. It’s difficult to imagine exactly what this would look like, but “less centralized” seems like an intuitive answer.
This issue is only compounded by the fact that new government regulations to ban incandescent bulbs are now in effect. Changes like this further harm competition by preferencing companies more able to adapt to arbitrary energy efficiency criteria.
So if you’re driving along at night and your vision is obscured by a strange, purple hue, remember that, although the light was the result of a manufacturing mistake, the impact of the mistake is predictable when you consider the incentives at play in government contracting.
