5 Best HPS Cannabis Grow Lights in 2021


iPower (400 Watt) HPS Grow Light


Do you plan on growing cannabis indoors? However, growing plants indoors has a few disadvantages, such as your plants not getting exposed to natural sunlight, but it can be remedied. It is possible to grow your plants indoors with the help of high performing high-pressure sodium grow lights.

HPS lights are able to deliver the intense light that the cannabis needs to grow and produce healthy buds. They work great, especially during the flowering stage, so your plants might just end up producing more than you expect after installing the HPS lights. HPS lights are often compared to basic lights, but they have a different design and performance. They work great in producing lumens for your plants when it is needed.

They also do way better than incandescent bulbs. HPS lights are 40% more efficient than other grow lights such as HID lights, LED grow lights and T5s. HPS lights have been used for over 100 years, and they are trusted to deliver on the job. They promote healthy reproductive stages of your cannabis growth.

How Does A Grow Light Work?

Sunlight works by emitting different wavelengths of light that can be invisible and visible to the naked eye. Plants use different light stages to reproduce during various stages of growth to promote fruition and maturity of the plant. Grow lights work by mimicking the spectrum of light to kick start the process of photosynthesis, which plants depend on to turn light energy into chlorophyll that the plants use to thrive.

The early stages of cannabis growth use shorter blue wavelengths to mature because the light is warmer and supports and promotes the delicate stages of growth. As the plants continue to mature towards reproduction, they become triggered by the strong, cool and long red wavelengths to bloom and reproduce. The lights mimic a cool, late evening and the shortening season that introduce plants into the harvest. Grow lights provide concentrated energy of different spectral wavelengths to ensure that your plants get what they require when they need it the most.

The HPS light consists of a ceramic arc tube that is supported by a frame inside a bulb, a glass bulb that is made to withstand immense heat, a stabilizer and a vacuum. For higher efficiency, the arc tube has a high pressure inside it. Inside the arc tube, you will find Sodium, xenon and mercury. The lamp is usually started with a pulse start, which is the most common way. The ballast has an ignitor built into it, sending a high voltage energy pulse through the arc tube, thereby starting the lamp.

The lamp’s ignition starts the HPS bulb by producing a white colour, which is the xenon heating up. After that, the mercury reacts to produce a bluish light, and then the Sodium reacts to emit the red/orange hue that we know.

What Is An HPS Grow Light

An HPS light is a high-intensity discharge light made up of a large bulb filled with gas. When two electrodes pass electric currents between themselves, they ignite the gases, and this causes them to light up. The difference between HID bulbs and HPS bulbs are the gases found in them. HPS gets its name from the High-Pressure Sodium that it uses to create the light glow.

HPS lighting systems include a ballast that powers the bulb and acts as a regulator for the energy needed to prevent the bulb from burning out too quickly. It uses a reflector or hood to focus the light energy where it is needed. It can also be found in an HID bulb.

HPS bulbs emit a red spectrum of light during the flowering stage of growth. But the absence of the blue spectrum of light isn’t suitable for the early stages of plant growth. For this reason, the majority of growers use LED or MH lights at the start of growth and then use HPS lights during the flowering stage.

Color Spectrum Of HPS Lights

An important factor to know about, especially when growing cannabis, is the colour spectrum found inside an HPS bulb. Cannabis plants tend to respond positively to the red/orange light that is emitted by an HPS light. A lot of growers and researchers have wondered why cannabis plants respond so well to the orange/red wavelength.

In order to answer the reason why, we need to know a little background information on cannabis. Cannabis is an annual plant, meaning that it completes its life cycle in one year. Cannabis begins its growth journey in late spring after all the dangers of frost have passed.

Cannabis is usually in their vegetative stage during the summer months. During that period the sun is usually high in the sky, and it emits a bright blue/white wavelength that the plants recognize. When fall arrives, and the sun starts to set, the cannabis plants take that as their cue to begin reproduction in order to ensure that the next generation is made before the brutal winter period begins.

This response to the change in season is known as a form of phototropism; this is where cannabis plants stop growing leaves and focus on producing flowers. The male flowers pollinate the female flowers, and after that, marijuana seeds are produced.

Most growers go through extreme lengths to keep the male plants out of their flowering rooms, so they do not pollinate their special females. At the end of many weeks, it results in resinous and dense cannabis buds.

You may be wondering how all this relates to HPS lights. HPS light produces a specific wavelength that mimics the daylight from winter days. This causes the cannabis plant to switch from its vegetative stage to its flowering stage. a lot of studies have shown that HPS lights are produced more than metal halide bulbs because they are able to mimic the orange and red wavelength of the sun effectively.

HPS Ballast

When your HPS bulb is turned on, it has a high amount of energy inside it depending on its wattage. If the power being supplied isn’t regulated, it will be dangerous. This is why there is a need for an HPS ballast.

The ballast in the HPS light regulates the amount of power that is sent to the arc tube inside the HPS bulb. The light will not be consistent if the ballast isn’t there to regulate the power. The job of the ballast is to maintain the right amount of energy according to the wattage rating.

If the ballast doesn’t perform its job, you would be burning through bulbs every few minutes because it would be overloaded with power. HPS bulbs are expensive, so it would be wasteful to keep burning through them.

Ballasts also help to keep your lights safe. Majority of the new digital ballasts come with automatic shutdown feature in case of a power surge. You won’t stay with your grow lights at all times, so the ballasts act as a regulator and a fail-safe device just in case of an emergency.

Types Of Magnetic Ballast

When searching for the best grow lights, you will be posed with the question, which type of HPS ballast to get. You can’t buy an HPS light without considering which ballast to go with especially because they go hand in hand.

Magnetic Ballasts

The magnetic ballasts use copper coils and steel sheets to conduct electricity. They are heavy materials because of this the magnetic ballasts are way heavier than the digital ballasts. They are also from an older generation. It has thereby been replaced with a more user-friendly digital ballast. This does not mean they are outdated and forgotten. A lot of growers still use magnetic ballasts because they are affordable, durable and easy to fix. Magnetic ballasts have withstood the test of time, and this gives growers the confidence they need to trust their grow setup.

Digital Ballasts

Technology has brought about the digital ballasts. They are more advanced when compared to magnetic ballasts. They come with amazing features such as dimming options, remote control function and in-built fans.

The dimming option is incredibly useful because there are times when you won’t need to use the full 100 watts of your HPS bulb. In some instances, it saves cost by using 50% or 75% of the bulbs total power. This is where you will see the true power of the digital ballast, the fact that it is able to dim the light to some percentages affords you flexibility when using an HPS bulb of 1000w, 600w or 400w.

Apart from the dimming light function, digital ballasts are also lighter in weight than their counterparts. The reduction in weight makes it easier to install your digital ballast inside your grow space.

Digital ballast comes with in-built fans to help regulate the overall temperature. Magnetic ballasts are quieter than digital ballasts, but they tend to become hot. The in-built fan in digital ballasts offers you the peace of mind you need while powering your cannabis operation.

All-In-One HPS System

When you are working with lower wattages such as 150w to 400w HPS bulbs, you may be able to find an all-in-one system which can be an invaluable tool in your garden. These type of systems include a hood, bulb and an attached ballast.

However, they can be quite heavy because they store all three components inside one hood, making it suitable for small scale cultivators. This type of system is also beneficial because they save you the cost of buying each component separately.

HPS Systems Hoods

We have discussed about HPS bulbs and ballasts, the next component to discuss which makes up the HPS system is the hoods.

HPS hoods come in varying shapes and sizes, and they help to spread light evenly, thereby increasing the light output. It also traps hot air which will be removed through an in-built fan. Hoods are made to evenly spread the light that is emitted by the HPS bulbs. This allows the light to be directed to specific locations and create an adequate light footprint for your cannabis plants.

They are also made with reflective materials that produce extra light. Hoods help boost the amount of light sent by the bulb to your canopy below through the reflective material, which could be white coatings, mylar or reflective aluminium.

The majority of hoods come with a glass bottom and two vent holes. When it’s combined with an inline fan and ducting, the hood is able to trap hot air produced by the HPS bulbs. Once the air is trapped, the inline fan and ventilation system will push or pull the hot air out of your grow space. Except you have placed air conditioners all over your grow space, it is very uncommon to use an HPS light without a hood.

Types Of HPS Grow Lights

When looking for the best HPS grow light, you will need to look for lights within this category. Here are the different HPS bulbs that are available on the market.

150 Watt HPS Grow Lights

The 150 watts grow light is the smallest type of HPS grow light. This light is effective in a closet type of space; the heat won’t be felt significantly, and it’s cost-effective. This bulb is suitable for people who don’t want to use LED, CFL and T5 lights. If you want to provide your plants with the benefits that an HPS light has to offer without appending too much, consider going for the 150w HPS grow light.

This wattage of the HPS grows light also comes in an all-in-one system. This system doesn’t weigh a lot compared to the next size, especially when paired with a small ballast.

400 Watt HPS Grow Light

The 400-watt HPS grow light has been known as the favourite grow light for small scale cannabis growers. These grow lights come both as stand-alone bulbs and all-in-one systems. But we are wondering what makes them so effective.

This wattage of HPS light offers you reduced electrical cost and heat production with high yields. For this reason, a lot of growers all over the world are convinced that it is the best type of HPS light. With the right planning, a 400w HPS grow light is a great introductory light for your cannabis plants.

A 400-watt HPS light can cover a 3*3 grow room if you plant your cannabis in a particular way. An important factor to focus on when using a 400 watt grow light is the canopy of the cannabis plant and not the undergrowth. This is because you cant compare the light penetration of the 400 watts grow light to that of the 600 watts or 1000 HPS bulb.

This means that your cannabis crop has to be bushy and short. The methods suitable for growing cannabis when using a 400-watt HPS grow light include the Sea of Green method (SOG) or the Screen of Green method (ScrOG). These methods of growing focus on the canopy of the cannabis where the largest buds will be produced.

If you intend to grow large plants, it would be best to use a higher wattage of grow light. The ideal place for 400 watts grows lights to be placed close to the canopy. When the light is placed closer to the canopy, the coverage will be greatly reduced. The main issue with a 400 watt grow light is the constant battle between proper coverage and the grow light’s efficiency.

You may be thinking that the 400-watt HPS grow light is great for a small space, but you should know that they produce quite a large amount of heat for their size. Don’t be surprised if you come back to your 2*2 grow tent to notice that your cannabis plants are wilting under the intense emission of your 400-watt HPS light.

If you want to have an enjoyable and easy-going system, it is best to have a proper ventilation system alongside your 400-watt HPS grow light system.

600 Watt HPS Grow Light

These type of grow lights are known as the most versatile grow light in the cannabis growers industry. You would think that this award would go to the 1000 watts HPS grow light, but instead the 600 watts HPS light is the most preferred wattage.

The 600 watts HPS lights are popular for their great canopy penetration, making them ideal for growing tall cannabis trees and dense bushes. With the additional 200 watts compared to the 400 watts, the 600 watts HPS grow light provides a significant boost in cannabis bud reproduction.

The basic goal of cultivating cannabis is for an abundant harvest. 600 watts HPS lights are known for saving you money on your electricity bill and improving your gram per watt ratio when harvest time comes around.

Many people ask if the extra 200 watts are worth the extra cost on electricity, but the answer depends on the size of the psace you’re growing in. Many long-time growers consider the 3*3 grow area as the best size, but the 4*4 area is also considered an optimal size. The 4*4 space gives you the right space for small and large cannabis plants.

If you want to increase the 600-watt HPS light’s versatility, you can purchase a digital ballast that comes with the dimming function. Doing this allows you to plan for the future in case you plan on expanding. Majority of growers keep their 600 watts HPS lights because they can always use them in different situations.

However, you should keep in mind that there will be an increase in your grow rooms overall temperature. You may feel like you’re walking into a rocket launch anytime you open your grow room or tent, especially because of the flooding lights from the HPS bulb.

If your ventilation system is adequate, you will notice that your cannabis leaves will be lifting their leaves to the light. It is well known that cannabis tends to respond positively to bright lights ranging from 600 watts to 1000 watts HPS lights.

1000 Watts HPS Grow Light

These type of grow lights are the largest that can be found in any garden. If you need full coverage for your plants, then go for the 1000 watts HPS grow light. They are known to emit breathtaking light; they are most amazing to people who haven’t seen it in person.

As your ballast ignites, you will be surprised to see how amazingly bright a 1000 watt grow light can be. After you have ignited the bulb, you will come to understand why these type of bulbs are only meant for serious cannabis cultivators who use top-notch cooling systems. If you don’t have an adequate AC system, you do not need to use a 1000 watt HPS grow light.

If you insist on using the 1000 watts HPS grow light, then make sure you’re mentally and financially ready. The light will leave you breathless in two ways; firstly, by the light intensity and secondly by the increase in your electricity bill.

If you cultivate on a small scale, it is best to stick to the 600 watts HPS grow light. However, if you’re a large scale commercial cultivator with a top-notch AC system and investor funds, the electricity bills won’t bother you much.

It is important that you do not try to use a 1000 watt HPS grow light in a small grow space. Doing this will cause your plants to suffer immediately, and it will cause your harvest time to be pushed back significantly. A 5*5 grow space is the bare minimum of spaces that you can use a 1000 watt grow light in.

When it comes to light penetration, this wattage of HPS glow light doesn’t have any problem, so you can safely grow tall plants, SOG, ScrOG and cannabis bushes. You can grow any and every style of cannabis if you are equipped with a 1000 watt HPS to grow light.

As we have said before, the cost price for running a dedicated 1000 watt HPS grow light is quite significant. For this reason, we will be reviewing mostly the 400 watts and 600 watts HPS lights. If you are certain that you can maintain running a 1000 watt HPS grow light, you will notice that you will be producing a lot of cannabis.


Before buying an HPS light, you need to know some important factors. The first factor to consider is if your ceiling has enough space to handle the HPS lights, you need to check a distance-from-foilage chart to know the right distance to hang the different wattages of HPS lights. If you have the right space for the HPS grow lights then there are some more factors you need to consider, these factors include;


When you are selecting which the HPS light to go for, you must decide on the right wattage. For small scale growers that do not intend on increasing their yield, the 400 watts HPS grow light is ideal for their garden.

If you choose the 600 watts HPS grow light, you may need to upgrade your room size in the long run. The 600 watts HPS grow light tends to increase your grow room’s versatility, depending on if your ventilation system can handle it.

Coverage Area And Room Size

Like various types of grow lights, HPS lights come in different sizes and wattages; this means that their coverage area varies. The wattage you choose should have adequate coverage over your plants and match your grow room’s hanging distance. The higher the light’s wattage, the higher the coverage area and more distance will be required from the canopy to the bulb.

If your grow space looks like a grow closet, it is best to go for a 400 watts HPS light and below. If the room is too small, a 400 watts HPS grow light will be too much for the plants to handle. You need to find the right balance between light intensity and adequate coverage. If you ignore these two factors, then your efficiency will reduce.

The best size of the room for a 400 watts grow light is a 3*3 room. If you use it in a larger space, your yield will reduce as you try to use it over a large canopy. You can use a 600 watts HPD grow light for a 4*4 and 5*5 grow room. As you increase your grow room, you can add an extra 400 watts to 600 watts to accommodate the new space.

You should have a predetermined space for growing before purchasing a grow light to match the space’s size. The available space should determine the wattage of light for the best coverage.

Single Or Double Ended HPS Bulbs

The single-ended HPS bulbs resemble a basic traditional lightbulb; it uses the basic Edison screw three that is easy to install. The double-ended bulbs look like fluorescent light because they are screwed at both sides, but they are considered to be 25 to 30 percent more efficient.

The double-ended lights are more expensive than single bulbs, but they come with different advantages. Majority of weed growers use the double-ended HPS systems for even distribution of light and maximum yields. However, it may be best to start with a more affordable single-ended HPS light if you’re a beginner.

Cost And Warranty

Cost is an obvious factor that everyone has to consider when buying a product. However, the average cost of buying an HPS grow light is less than that of an LED light. Avoid any product that is incredibly cheap because it is cheap for a reason, and it’s definitely not a good reason.

Let us dive into the reviews of the best HPS grow lights, their specifications and features. Once you have gone through this guide, you should know all you need to know about HPS grow lights.

The Best HPS Cannabis Grow Lights Are Reviewed Below

Below are the top best HPS grow lights for cannabis.



This HPS system is a great system to work with, it is specifically made for small grow rooms, or it can be used as an auxiliary light. It features a reflector with an in-built ballast; it also comes with air cooling and ventilation functions to help get rid of hot air. It has total coverage of four square feet, and this is enough to aid the growth of a few flowering cannabis plants through the winter months, or it can help a small garden to produce even when it’s out of season.

This system comes assembled out of the box and ready to plug in. it has a white powder coat finish that prevents rust from accumulating on its surface during humid periods. Its housing is long-lasting and durable. It comes included with a hook but not a hanging ratchet system. It also comes with a 120 volt, seven-foot grounded power cord.

Key Features:

  • 16,000 lumens grow light
  • Two-year warranty
  • Complete grow fixture


  • Brand: SUN SYSTEM
  • Weight: 7.75 Pounds
  • Dimensions: 18.1 * 9 * 6.5 inches
  • It is lightweight
  • It operates almost silently
  • It uses a very low amperage
  • It doesn’t come in discreet shipping boxes
  • It is quite difficult to get a hold of the customer support


iPower (400 Watt) HPS Grow Light

If you require a complete HPS grow light, then this light is suitable for your needs. The system features two bulbs and a timer that functions properly. It comes with a digital dimmable ballast that does not make any buzzing sound. The only sound you will hear from the ballast is the small fan.

The digital ballast in this system can be adjusted to 50, 75 or 100 percent for the best coverage and maximum efficiency. The lumens it provides you with is more than you would have with a magnetic ballast. The bulb has a rate of 400 watts and a colour temperature of 2100k. The light it emits allows the plant to go through photosynthesis in order to grow and reproduce.

This system comes with a wing reflector that does not produce any refraction and provides your plants with the best coverage. However, you can always customize your setup.

Key Features:

  • 400 watts bulb
  • Dimmable options
  • Heavy-duty, 8 feet power cord
  • Digital ballast
  • Adjustable ratchet
  • Wing reflector
  • Hydroponic S-plug


  • Brand: iPower
  • Model: iPower (400 Watt HPS MH) Digital Dimmable Grow Light
  • Weight: 1.1 Pounds
  • Dimensions: 21 * 5 * 17 inches
  • Material: Aluminum
  • The bulb is CE certified, and UL listed
  • The digital ballast has a dimmable feature and also quiet
  • It uses less power and has no acoustic resonance
  • Its design ensures that it has no exposed wired
  • The light lasts long with no flickering
  • The temperature control is quite difficult because of the wing reflector
  • Sometimes the MH bulb might not ignite



iPower is a well-known name in the industry; they offer a wide variety of choices when it comes to HID lights. This HPS system has a digital ballast with the dimming function; it allows you to control the output of light from 50%, 75% and 100% intensity. This lets you avoid having to adjust the height of your setup as your plants mature.

It comes with a wing refractor that provides you with the best coverage and also reduces cost. However, it does not have a cooling system, so it is important that you have an adequate cooling system. It comes with an in-built 10-foot heavy duty power cord and hanging ratchets. These components make it easy to mount and move this HPS light about.

Key Features:

  • Digital dimmable ballast
  • 8 feet power cord
  • Adjustable ratchet
  • 19-inch wing reflector


  • Brand: IPOWER
  • Weight: 11 Pounds
  • Dimensions: 19 * 19 * 6 inches
  • It is simple yet powerful
  • The bulbs have a one-year free replacement
  • It improves your overall yield
  • It causes a lot of heat
  • Sometimes it may be shipped roughly but it’s covered by the warranty


Hydroplanet Horticulture (1000W) HPS Grow Light

If you own a hydroponic gardening space and need the right light to support your plants, this HPS grow light will suit you well. The light has a 1000 watt rating; however, it has adjustable power settings that allow you to bring it down to 600 watts or 400 watts. This grow light has an automatic system that switches it from MH and HPS bulbs.

This HPS lamp is not like the standard lights; it is able to use both 120 volts to 240 volts. It is capable of operating with a 1000 watt magnetic or digital ballast. It also comes with an integrated cooling fan that allows you to control the temperature. It prevents the ballast from overheating the system. It features a wing reflector that is designed to offer wide and bright light coverage.

Key Features:

  • Digital ballast
  • 19-inch basic wing
  • 24-hour timer
  • Heavy-duty rope hanger
  • 2 years warranty


  • Brand: Hydroplanet
  • Model: Hydroplanet Horticulture (1000W HPS MH) Grow Light System
  • Weight: 13.72 Pounds
  • Dimensions: 21.8 * 14.6 * 8.4 inches
  • It automatically converts between HPS lights and MH lights
  • It is ETL listed, and CE certified
  • It supports two voltages 120V and 240V
  • It has an in-built fan that regulates the operating temperature
  • The lamp is compatible with both magnetic and digital ballasts
  • It has an adjustable power setting between 600 watts to 400 watts
  • Sometimes the bulb may fail to ignite



This HPS grow system provides you with everything you need to grow your plants. It comes with an air cool hood, a ballast, timer, hanging ratchets and an HPS and MH bulb. It emits a blue spectral wavelength in order to provide your plants with what they need to grow. It also comes in a 400 watt and 600-watt support. Its ballast is made out of steel and aluminium, and it allows you to dim the light to control your light output.

It comes with an air cool hood that helps reduce the heat that is caused by the bulbs. However, if you have proper ventilation in your grow room, the glass on the hood will stay cool even after hours of consistent use. It comes with an 8-foot power cord that can be used 110 to 240-volt outlet.

Key Features:

  • Dimmable, fan cooling ballast
  • A reflector
  • Pair of hangers
  • 56,000 lumens
  • Dimmable option


  • Weight: 23.5 Pounds
  • Dimensions: 24.41 * 17.72 * 9.45 inches
  • It offers you proper coverage
  • It stays cool to the touch even after hours of use
  • It uses less energy
  • The sealing of the glass could be better
  • It can be difficult to reach customer care

Buying Guide Questions

What’s better HPS or LED grow lights?

HPS lights use more electricity than LED lights, and they also produce more heat, and often need an adequate ventilation system, which makes them less efficient than the LED lights.

What is HPS grow lights?

HPS stands for High-Pressure Sodium, and they are half of a basic high-intensity discharge (HID) system. They produce a red spectrum of light, and they are used mostly in the flowering stage.

What is the best HPS grow light? How much area does a 1000Watt HPS cover?

Our best HPS grow light is the SUN SYSTEM 150W HPS PLUG AND PLAY GROW LAMP. A 1000 watt HPS grow light can cover a 7*7 feet area.

Can you use HPS for the whole grow?

Yes, you can use HPS light for the whole grow and increase your overall output. They tend to improve your yields.

Are HPS lights dangerous?

These type of lights tend to produce a lot of UV rays; however, their casing is usually made out of filters to prevent the rays from affecting anyone.

How many plants can you put under a 1000 Watt HPS?

A 1000 watt HPS light can cover from 16 to 19 plants

How often should you change your HPS grow lights?

The bulbs in the grow lights need to be replaced once a year because they lose 20% of their output in a year.

Is HPS best for flowering?

Yes, they are great for flowering because they produce a massive amount of light.

How much does it cost to run a 600-watt HPS?

It costs about $31.92 a month to run a 600-watt HPS light.

How many plants can you grow under a 600-watt HPS?

You can grow about 16 plants under a 600-watt HPS grow light.

Is 150w HPS enough for one plant?

Yes, a 150-watt HPS light is suitable for 1 to 2 plants

Is 1000w HPS too much?

A 1000 watt grow light is a bit excessive, especially if you have a small garden. But if you run an extensive garden, you can use a 1000 watt HPS grow light.


With this article, you should know all you need to about HPS grow lights and which wattage is best for your garden or grow room.


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