HPS lights have long been the industry standard.
Before LED came along and switched things up, the majority of grow projects heavily relied on the usage of HPS lights.
To spot the difference it’s important to look at LED vs HPS grow lights in detail.
Disclosure: This post may contain affiliate links. If you shop through the links on YardThyme, we may earn an affiliate's commission from qualifying purchases at no additional cost to you. For more information, read full disclosure here.
Let’s Go Back to The Basics
HPS stands for High-Pressure Sodium. According to Sensi seeds, the lights send a pulse of energy through a pressurized quartz tube filled with vaporized sodium.
These bulbs are known for emitting a yellow-red spectrum of light and give off a lot of heat.
The yellow-red hue can promote fruiting and blooming, but the plants tend to elongate due to a lack of the blue spectrum when HPS is used exclusively, with no outdoor or natural light.
HPS makes a good supplement light, used with full-spectrum lighting. The light is also able to give off the optical and infrared light, which attracts insects and pests.
HPS lights can be doctored with xenon and mercury to give off more blue lights if the grower wants to use HPS exclusively.
HPS lights are known for their ability to facilitate maximum yields, making HPS lights a no brainer before LED came along.
They are some of the most powerful lights on the market, and the choice to use them is understandable.
LED means Light Emitting Diode. Technically that’s diodes with an ”s” because there are many diodes together forming an LED light.
These diodes can emit red, blue or green light, and most grow lights offer a balance of the three to mimic natural light.
LEDs are popular because they are small, durable and have a long life. They make it easy to manipulate the color spectrum in your grow environment, and they are cool, not giving off a lot of heat.
The Stand-Off – HPS vs. LED
Let’s outline the differences between HPS and LED so you can determine which is best.
If you want to get to the point quickly, scroll down to see the LED vs HPS comparison chart.
Costs to Run
It’s challenging to manage an indoor growing project. You encounter many costs trying to replicate nature behind closed doors, and maintaining and mimicking sunlight may potentially cost a big chunk of change. So doing a comparison on LED vs HPS lights is crucial.
Ideally, you’ll want a system that produces the maximum amount of light for the best value. One of the biggest differences between HPS and LED model lights is the way they utilize electricity.
HPS lights are kind of old school.
Compared to a lesser quality grow lights, good HPS lights will generate a spectacular amount of light, but they’re sucking up more electricity to make that light.
HPS lights are power-hungry and if energy consumption is the main concern, HPS is the loser on this point.
LED lights will also generate a fair amount of light, but their advanced technology allows them to do so more efficiently, so they use less electricity compared to the amount of light they emit.
LED lights are the energy-efficient winner, hands down.
This is the one thing that all must agree when looking at LED grow lights vs HPS.
Amount of Light
Between HPS and LED, the light intensity is just about the same.
While it may appear that LED lights aren’t as bright to the naked eye, the difference is mostly in the quality of light being produced.
HPS lights can be blindingly bright, much like the real sun. While LEDs are a little duller, they’re doing a better job of supplying all the different spectrums of light required at different stages of the growth cycle.
Light Spectrums of HPS vs LED
Natural daylight contains a full spectrum of light. The spectral quality of the light has an effect on your crop.
The spectrum of light and distribution of that spectrum can affect the way plants grow, taste, resist insects and more.
Researchers are still discovering the ways in which all types of light affect plant growth. Some spectrums are better for germination and root growth, while some light, like HPS spectrum lights, perform well during fruiting and flowering.
HPS systems don’t produce the same full-spectrum light frequencies that the sun produces, but the infrared spectrum light HPS produces are perfect for fruiting and flowering, which is why many cannabis users prefer HPS lights, use them in combination with LED’s or use HPS during the flowering cycle.
Mark at Plantzoid.com writes:
The plant wants to capture all of those extra photons but needs CO2 to help with that part of the ATP cycle. You can’t get that extra yield with LEDs. Just turn your CO2 off because it is making no difference or switch to HPS for your flowering cycle if it’s feasible.Mark
LED lights will give you genuine ultraviolet and infrared that you can’t get from other systems and is a good lighting system, too.
This makes LED light fully suited to the entire growth process, and that’s not something an HPS light can offer you.
You also have the capability of experimenting with the blue and red values to come up with a custom lighting creation that may be more beneficial to your plants than a preset configuration, or even more beneficial than natural sunlight.
- HPS – Awesome during the flowering cycle, OK during the rest of the life cycle.
- LED – Full spectrum light is good for all cycles, but may result in smaller yields if it is the only type of light used.
Heating and Cooling
Maintaining the temperature in your grow room is likely a constant struggle. It’s not easy to play Mother Nature with electronics, and you don’t need anything to further complicate that process for you.
In warm or hot climates, HPS lights are a real killer. Not only are you trying to fight the outside influence on your grow room to maintain the perfect temperature, but you also have the heat emanating off of your HPS system.LED lights don’t really put off much heat. It’s one of their main benefits.
All lights will put off a little heat, but with an LED, it’s not anything that you’ll need to struggle to keep balanced. You’ll never have to worry about them burning your plants or dehydrating your environment.
There are certain circumstances, such as harsh winters and cold or mild climates, where you may find that the heat from the HPS lamp is beneficial, there are other HOT environments where the radiating heat is not ideal.
Think Sudan, Mexico, Latin America, Thailand maybe?
Hands down, at harvest time, growers always seem to be pleased with their LED harvest if high quality LED lights are used.
On the other hand, many long time growers still use HPS, especially for flowering, because of HPS’s reputation for vigorous flowering and larger yields.
That said, Both can provide decent yield, but be careful with LED and make sure you use a high-quality light, which is m small-scale growers should stick to HPS lighting if they want to save money, with double-ended bulbs being the best option for higher wattage fixtures, say 1000 W. more pricey than an HPS light.
According to HighTimes Magazine:
One of the biggest advantages LED has over HPS is the average lifespan of the bulb. While your typical HPS setup will give you about 10,000 hours of light, that’s nothing compared to what you’ll get from an LED system.
Most LED systems boast an astonishing 50,000 hours of light before they need replacements, with some systems claiming up to 100,000 hours of light time.
That’s a decade and a half. Because of their sheer strength, LED lights will continue to operate above-average functionality even if a few diodes burn out here or there. LED systems are the more efficient choice, and it’s hard to argue anything contrary to that.
HPS lights are colossal. Because of their sheer size, you may find that you need to place them carefully.
You need the proper distance between the plants and the light, especially because you wouldn’t want the heat to fry your plants.You can place it just about anywhere to illuminate a large area, including closer to your plants.
You won’t have to worry about them getting scorched, or any other negative implications relating to the temperature.
Pros and Cons of HPS vs LED
In this LED vs HPS comparison chart, we can see that there are in fact many differences between the two.
So let’s break them down even more.
- LED Provides Full Spectrum Light.
- LED lights produce far less heat.
- LED lights use much less electricity vs light output.
- LED lights last for more than 50,000 hours.
- LED lights generally don’t need a reflector.
- Usually less expensive to purchase than LED.
- HPS produces a high amount of infrared light, delivering an abundance of bud creating photons during flowering.
- HPS put off heat, maintaining a warm climate in the grow space.
- HPS lights are rated according to industry standards so you know what you are getting.
- LED light needs to be high quality to get good performance, and high-quality LEDs are expensive.
- There are no industry standards for LED and they tend to suffer quality problems.
- LED lights do not produce a high quantity of infrared light and photons that cause high yield like HPS.
- HPS lights use a lot of energy, HPS lights are power-hungry.
- HPS lights do not offer full-spectrum light as LEDs can.
- HPS lights put out heat and are not ideal for HOT climates.
- HPS bulbs do not last as long as LED lights, maybe 3 growing seasons.
Who Wins The Battle of HPS vs LED?HPS lights are good for small growers, at home gardeners with 2 or three plants.
HPS lights are not crazy expensive and consistently produce a good yield. HPS lights can be laser-focused on the few plants of an individual grower delivering bud producing photons en masse.
LED lights are the best choice for large operations because the electricity cost to light a large area is not suited to HPS lights.
High Quality LED lights can produce the yields HPS gives, at a fraction of the cost of energy, but they cost a lot upfront.
So there you have it. A detailed comparison between LED vs HPS lights that should give you the information you need in order to choose the one that is best for you, the plants you are growing and the environment they are being grown in.