Led Grow Lights Vs Hps

The choice between HPS and LED lighting in your grow room is a common one. It's not like you're alone. This is one of the most often asked questions about cannabis farming.

There has been a lot of confusion throughout the years about which approach is best. Both political parties have their share of proponents. Why so much commotion?

The fact of the matter is that technology has evolved tremendously in the last several decades.

Even in the previous five years, the technology for growing lights has advanced by leaps and bounds. This means that what was true in the past may no longer be the case. LED and HPS both have advantages and disadvantages.

The following information will help you decide if this is a good fit for you.

HPS Grow Lights

HPS Grow Lights

High-pressure Sodium (HPS) lamps may put out a lot of light. Because of this, farmers have been using HPS lights for years. During the flowering stage, light is essential and has been shown to improve harvest yields. HPS grow lights, with their high levels of light output, may produce the optimal conditions for the flowering of cannabis. HPS lights can be set up at a low cost as well. In contrast, the high output of High Pressure Sodium lamps generates a great deal of heat in the opposite way.. Using HPS grow lights in many circumstances necessitates additional ventilation to ensure adequate airflow. Costs are likely to rise dramatically as a result of this. High-intensity lighting also uses a lot of energy, which raises costs and harms the environment even more.

It is possible to boost cannabis flowering by using HPS grow lights that produce a high amount of light.

There are numerous HPS grow lights to choose from, and as a result, the selections are more standardized.

HPS grow lights are less expensive to set up than LED lights at first.

In comparison to LED lights, HPS grow lights consume more power and are less energy-efficient.

In comparison to LED grow lights, the lifespan of HPS grow lights is significantly reduced.

Airflow and ventilation are critical for HPS lighting because of its high intensity.

Temperature control can be difficult, especially in small settings.

The long-term expenditures of HPS grow lights are astronomical.

LED Grow Lights

LED Grow Lights

With the rise in popularity of LED, or Light-Emitting Diode, grow lights, The way we cultivate things has been transformed by technological advancements. Until recently, HPS lights were the sole option. Even the largest commercial cannabis farms now use LED lights. LED grow lights are far more energy-efficient than HPS lights. To produce the same yields as HPS lights with substantially less energy, high-quality LED grow lights can be used in place of HPS. Because of this, many cannabis farmers believe LED lights to be a more environmentally friendly alternative for indoor production than fluorescent lights. They are also cost-effective. Best LED grow lights are more expensive than HPS lights at first, but they save money in the long run. LED lights have a long lifespan, so you won't have to keep buying new ones all the time.

LED grow lights use less energy than incandescent bulbs. As much light as HPS lights but with significantly reduced energy use.

With less heat generated than HPS lights, LED grow lights eliminate the requirement for extra ventilation or airflow systems.

Compared to HPS lights, LED grow lights are more compact, allowing for more grow space.

In terms of shelf life, LED grow lights are excellent.

LED grow lights require a larger initial expenditure than other types of lighting. In the long run, however, their long shelf life can save money.

There may be a problem with the amount of heat produced by LED grow lights in colder climates.

Comparing choices is more difficult because of the absence of standardization in LED lights

Benefits of using HPS lighting in Commercial Grow:

  • At least in the beginning, they are less expensive than LEDs.
  • Standardization and predictability are hallmarks of HPS lighting technology.
  • When it comes to scaling up, HPS lights are more convenient.
  • Light that is useable to cannabis plants is known as "photosynthetically active radiation," or PAR. HPS cannabis grow lights are capable of creating this PAR.

Although LED grow lights initially cost more than HPS lights, they really end up costing less in the long run because of their lower power consumption and the absence of traditional maintenance costs. HPS grow lights, despite being less expensive, lose their brightness with time and require more electricity and upkeep. LED grow lights, on the other hand, have a 50,000-100,000-hour lifespan and do not lose intensity with time. LEDs, on the other hand, are still unable to match the immense output of HPS lamps.

The Downside Of Opting For Hps Lights

  • With HPS grow lights, additional ventilation and temperature monitoring equipment is needed to keep the grow room at the right temperature.
  • When compared to equivalent LED lights, HPS lights use significantly more electricity and require significantly more maintenance over time.
  • Replacement of HPS grow bulbs is required every 12-18 months due to a decrease in intensity.

Benefits of LED grow lights

  • LED grow lights currently compete with HPS lights, although using nearly twice as much power.
  • All-in-one LED grow light fixtures are more convenient to use in tiny settings. Even closer to cannabis plants can be placed LED grow lights because of their lower temperatures.
  • Even in harsh or arid settings, the LED light temps make it easy for growers to maintain appropriate heat levels.

Negatives of LED grow lights

  • The initial investment in LED grow lights is still higher than that of equivalent HID choices now available. However, long-term savings in energy and operational expenses may offset this.
  • Because LED grow lights are not standardized, it is impossible to compare and contrast bulbs or lighting systems.
  • When growing cannabis in cold, indoor environments, growers may need to complement their LED lights with a HID light in order to keep the plants warm.

What's the difference between LED and HPS lighting, exactly?

The long-term savings that can be realized by using LEDs in the growing process are becoming increasingly difficult to ignore as the technology improves. A combination of LED and HPS illumination has been shown to boost yields while reducing energy use by as much as 80 percent, according to certain research studies.

Which Option is Better?

What kind of grow lights should you be using? Yes, both solutions have their advantages and disadvantages. Each has its advantages and disadvantages. LED lights, on the other hand, are preferable unless you're growing in sub-zero conditions. There are just more advantages to using this kind of transportation. Using LED lighting saves money in the long run, reduces energy consumption, and does not require additional equipment. You may be surprised at how economical high quality LED lighting has become despite the fact that it costs more initially than HPS lighting. The market has grown to the point that a wide range of alternatives are now available. Investing in a high-quality LED lighting system now will save you money in the long run. It doesn't matter how big or little your organization is; we've got the right LED lighting for you!

The Test

This study assessed 32 tomato plants per light source, which were grafted from clones to ensure uniformity. It's based on a variety of metrics, but a handful of them help us understand how well they've grown:

  • Leaf Area (growing power)
  • # of Leaves (growing power)
  • Fresh Weight (plant structure)
  • Dry Weight (plant structure)
  • # of Flower Buds (beginning flowering results)

At the end of our life cycle, we hope to have achieved excellent marks in all of these categories. There is a direct correlation between larger leaves, heavier stems, and more flower buds with a larger crop.

Colors and their combinations have a profound impact on the growth of plants. We can now cultivate superior plants in our own homes according to the most recent scientific findings!

Now, let's get down to the business at hand. As a seasoned grower, you'll know these familiar faces.

Contestant #1: Purple LED Grow Lights

These "narrowband" LEDs, which were developed in the 1990s, are still in use. Each LED can only provide a limited color spectrum.

Because Chlorophyll A/B pigments absorb red and blue light, Blurple LED makers believe that plants consume red and blue light the most.

A broad variety of "LED hues" (aka multi-band) are used in this type of illumination in order to provide a spectrum that matches as nearly as possible the graph of Chlorophyll absorption.

Furthermore, these manufacturers contend that HPS is inefficient because it produces too much green and yellow light. This adds a new layer of suspense to the showdown. Some genuine results are about to be shown in this presentation.

White LED lights may also be mentioned in the same breath as the claim that yellow/green light isn't necessary for plant development.

Also, this group believes that blue is associated with the vegetative and red is associated with the floral. To find out whether or not your LED lights are performing what you want them to, use switches!

One of the most popular purple grow light manufacturers, Kind LED Grow Lights, has provided the following graphs. Others in the industry have shared same sentiments.


Is it possible that they're right? Is it true that plants solely utilize red and blue light sources? Is it a waste of yellow and green?

Contestant #2: White LED Grow Lights

Our culture is becoming increasingly reliant on white LEDs, which are getting more and more popular. Light emitting diodes (LEDs) are being used in everything from street lighting to flashlights.

The use of a "phosphor" in an LED can produce a rainbow of colors (in contrast to narrowband LEDs), thanks to huge advances in this technology.

Like a prism, a phosphor disperses light into a kaleidoscope of hues. Shape and curve of spectrum are designed to influence how color appears to human eyes. White LEDs will always adhere to the color temperature and accuracy criteria of "Kelvin" and "CRI."

Designed to be seen by humans, white LEDs are ideal. For efficiency and color consistency, LEDs are designed to produce a color that meets the Kelvin and CRI standards. Color selections are rather limited because they are "locked" within particular shapes of the spectrum. See this post if you'd want to understand how to go beyond white grow lights for plants.

When using white LEDs, it is important to keep in mind that green and yellow are the hues that seem brightest to the human eye. Most LEDs are destined to spend their entire lives serving humans, not plants!


In spite of their lack of certification and design for plants, some growers have discovered that these LEDs perform well since they produce a wide spectrum of light, not only red and blue.

Many LED manufacturers claim that their products are more efficient because they match the "McCree PAR graph" or "fit inside the HPS graph."

This graph, acquired from Nextlight LED Grow Lights, is a frequent one used by white LED grow light manufacturers. There are two lines: a white LED (green) and a spectrum of a High-Pressure Sodium bulb (blue).


No, I don't believe white LEDs can grow as fast as HPS. Is the HPS spectrum depicted in the graph above even a match?

The "McCree Curve," as it appears in the original scientific study by Dr. McCree, is shown below.

McCree Curve

The White LED appears to "match" this curve's contour.

There are valid scientific graphs showing the benefits of LED lighting for plants from both the purple and white LED manufacturers... So, who's going to come out on top?

Contestant #3: High-Pressure Sodium (HPS) Grow Light

It's time for the king to arrive! The best grow light on the market. What do you think about the HPS?

As street and warehouse lighting became more commonplace in the 1970s, the High-Pressure Sodium (HPS) bulb became the standard. I couldn't help but notice the "yellow glow" about me.

This bulb was first used to grow plants, and now growers everywhere swear by it. For flowering, it has a wide range of colors, including a lot of yellow, red, and even far-red.

In terms of growth, how will it fare? Will it be able to compete with LED technology?

Generally speaking, HPS is not recommended for vegetative growth due to its low concentration of blue, which can lead plants to stretch out. When using HPS in vegetative development, does it make sense to avoid it because of its spectrum? Will plants have a lanky appearance, with little leaves and a weakened structure? V

Green and yellow light may not be what plants are looking for at all...

Spectrum Composition

Okay! The spectrum compositions utilized in the laboratory test are shown here.

With the aid of these diagrams, you can see exactly how many colors there in each spectrum. When looking at a spectrum curve, a detailed breakdown is useful because it's not always evident.

Percentages and color ratios are crucial when discussing photobiology. The plant's response to a spectrum can be deduced from these clues.

Spectrum Composition

Let me know what you think. Is the Chlorophyll absorption-optimized red and blue spectrum likely to take the lead?

In terms of power consumption, does green light in the white LED spectrum have a negative effect on it?

What about HPS's very small quantity of blue?? In veg, will plants become lanky and frail?

Let's get this party started... Prepare yourself for a shock.

The Results

The Results

What astonishment! Always keep in mind that in a lab setting, all of the lights were properly calibrated to have the same level of intensity in the same environment. This is a fairly accurate test because 32 plants were utilized for each wavelength.

HPS scored a perfect 100 percent since it won every single category. A percentage of that score is used to measure the other two contenders. This indicates that purple LEDs are only half as efficient as white LEDs, and white LEDs are lagging by a quarter.

Additionally, this means that LEDs will need to provide more light to obtain the same outcomes as HPS. This is one of the reasons why a quick Google search for "LED light burn" may turn up horror stories. For the same effects, more light is required – oh no!

If you’re a data person, check out the results table below:

Fresh Weight (g) Dry Weight (g) # of leaves Leaf Area (cm2) Flower Buds
Purple LED 26.5 2.3 8 724.3 2.3
White LED 48.8 3.8 9 1117.1 4.9
HPS 67.3 5.9 10 1269.6 7.3

Even after studying this study for almost a year, I'm still amazed by how much the spectral content affected performance!

Plants display diverse properties depending on the color of light they are exposed to. When it comes to plants, they're complex, living organisms that use light information to learn about their surroundings! It's fantastic...

Is it possible to identify the wavelengths that triggered the growth changes?

There was an obvious winner in terms of performance, I hope you will agree.

It's still the king for HPS growers! In terms of vegetative development, the HPS provided the largest leaves, heaviest structure and most flower buds – a certain winner for the tomato leading to an abundant flowering crop if you can handle higher plants in your grow arrangement.

Add some blue into the spectrum for stretching purposes now, if necessary. We can, however, only go so far before yields begin to decline.

Purple LED Leaf Size

Purple LED Leaf Size

White LED Leaf Size

White LED Leaf Size

High-Pressure Sodium Leaf Size
High-Pressure Sodium Leaf Size

Is it possible that the blue light would have aided in the growth of the plant? Observe how the leaves shrank in size as the amount of blue light rose. Lessening the rate of increase in power!

It's a nice, bright white light. The results were clearly boosted by the use of green light. Chlorophyll absorption alone doesn't tell us all we need to know about photosynthesis. You'll need a lot of green or yellow light if you're going with an LED.

For those of us who have already invested in LED lighting installations, this could spell trouble. It's possible that LEDs need up to 100 times as much light as HPS does to accomplish the same outcomes. That's what I call effectiveness.

What will happen to LED?

It's not like that at all! There was no clear winner among various LED technologies when it came to promoting plant growth. There must be an alternative...

Then there's that.

You're going to love this... LED technology was also tested as part of this scientific study.

The final product is breathtaking.

It is possible to get the same outcomes as HPS with LED technology.

The findings are here. HPS has been outperformed in some situations...

Recall that we're all working at the same intensity, but only certain hues in the spectrum are responsible for this tremendous growth surge.

Do you know what's behind this huge increase in efficiency?

Is this the end for LED

Related article: LED vs Fluorescent Grow Lights

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