LED vs HPS Review

When it comes to choosing the best grow light for a given situation, many indoor gardeners find themselves choosing between LED vs HPS. LEDs, or light emitting diodes are relatively new to the market and many people do not understand some of the benefits and disadvantages associated with them. For the best led grow lights and best grow tents.

The other choice is often an HPS, or high pressure sodium bulb. When it comes to the debate about LED vs HPS, some individuals definitely have their favorite style of grow light. In order for a person to determine exactly which type is best for them, it is important to understand the pros and cons of each.

Energy Efficiency​

​One of the essential factors in the LED vs HPS debate is the matter of energy efficiency. There is really no comparison about the energy efficiency of LED vs HPS. LEDs use only a fraction of the electricity required by high-pressure sodium bulbs. This makes them an excellent choice for anyone that puts a premium on low energy usage. LEDs are so energy efficient that they can actually be run entirely off of solar panels. This has made them a favorite among individuals that wish to 'go off the grid.


Cost is also an important factor to many individuals with choosing between LED vs HPS. LEDs can be substantially more expensive than high-pressure sodium bulbs. While this initial investment may make them seem like a bad choice, it is important for a person to keep in mind that LEDs have a life span that is a great deal longer than HPS bulbs. If an individual is interested in getting the longest amount of usage possible then it may be easy for them to choose between LED vs HPS. In the end, the best choice is the one that works for the individual.

​Deciding between LED grow lights vs HPS is something that many indoor gardening aficionados may find themselves facing. The fact is that each light is superior to the other in certain circumstances. In order to choose between these type of indoor garden lights, an individual will need understand a few important factors about each type of light as well as keeping in mind their particular set of needs. There may be certain situations where one is easily the superior choice to the other. While gardeners have had excellent results with both, there is no right answer.


One important thing to keep in mind when choosing between LED vs HPS is that LED grow lights run incredibly cool. This may be very beneficial in some situations but there are other occasions where it may be preferable to have a warmer light. For example, a person that is growing plants in a cool area, such as a basement or garage during the winter months may find that the choice between these type of closet garden lights is an easy one. The heat provided by high-pressure sodium bulbs may be just the thing to keep plants healthy during colder times of the year.

If, on the other hand, an individual is choosing between LED vs HPS for plants that are grown in a very tight space, high-pressure sodium bulbs may be entirely too hot for the plants. In fact, many experts recommend that a gardener install some type of ventilation system in order to keep the area from being too warm if they are using HPS bulbs. Adding a fan or keeping a window open may make it easier for a person to choose between these type of lights. Because of their cooler temperature, it may not be necessary to have any extra ventilation if a person chooses LEDs. A person choosing between LED vs HPS should also keep in mind that it may be necessary to add some kind of ventilation to the area if they choose high-pressure sodium bulbs.


Price is also an important factor when choosing between LED vs HPS. LEDs can cost quite a bit more than their high-pressure sodium counterparts. This higher initial price may make it easy for people to decide between which type of light to use. If price is an important factor then a person should also consider the overall cost of ownership rather than just the purchase price. Although they may cost more initially, LEDs can be less expensive to own the long run because they require less energy and outlast high-pressure sodium bulbs by several lifetimes.

Finding the right grow light system for an indoor garden is not as simple as it may first appear. A person has a wide range of choices when it comes to choosing a indoor system set up for their plants. A common choice for many individuals boils down to LED vs HPS. LEDs, or light emitting diodes, have not been around very long and many people may not understand some of the advantages that come from them. On the other hand, HPS, or high-pressure sodium bulbs, are popular with many indoor gardening enthusiasts. The LED vs HPS debate often comes down to a couple of key factors.

Important Factor

One of the important determining factors when it comes to choosing LED vs HPS is the fact that LEDs cost significantly more than high-pressure sodium bulbs. The price difference can be quite large, especially if a person needs a large lighting system set up for a big indoor garden. Before ruling LEDs out completely, however, a person should consider the entire cost of ownership rather than just the initial purchase price. If purchase price alone was the determining factor, the LED vs HPS debate would be an easy one.

Because LEDs use only a fraction of the energy required by high-pressure sodium bulbs, they can be much more cost effective in the long run. It is also important to keep life span in mind when choosing between LED vs HPS. Although high-pressure sodium bulbs have a decent life span, they simply cannot compare to how long LEDs last. Cheaper energy bills and fewer replacements may make it easy to choose between LED grow lights vs HPS. A final important factor to keep in mind when choosing between LED vs HPS is the amount of heat put out by the bulbs.

Your lighting system is one of the most important, and most expensive aspects to your grow system. Having a good grow light system can make or break the quality of your end product. Today, we are going to discuss HPS light systems. HPS, or High Pressure Sodium, lights are part of the grouping called HID (High Intensity Discharge) lighting. This type of lighting is the most popular among all growers around the world due to the high lumen output.

High Pressure Sodium

High Pressure Sodium Bulb

HPS lights are used during your flowering period of growing. This is because of the particular spectrum of light that is given off by these types of light systems. High Pressure Sodium lights give off an orange-tinged glow that could be compared to the harvest sun. It is said that this spectrum of light significantly enhances density and volume of the harvest due to the increased stimulation of the floral hormones.

Metal Halide

Metal Halide Bulb

MH, or Metal Halide grow lights are used during the vegetative stage. Metal Halide bulbs produce a bluish bright light which mimics the bright spring sun, and using MH bulbs during the vegetative stage will promote short, bushy growth in your cannabis plant. A quality LED grow light can produce light in the blue and red spectrum to mimic MH & HPS light wave.

Flowering plants like cannabis need a significant amount more light than vegetative plants, so it is highly advised to use an HPS system over your typical fluorescents or Metal Halide lighting systems during the flowering stage. Many growers will actually leave a Metal Halide grow light in their grow area along with introducing a High Pressure Sodium bulb as well. This way their light has drastically increased and they are able to give their plants all the light they need from the correct spectrums.

Whether you decide to use an HPS grow light system or you prefer MH, the general consensus is that the HPS systems are the best used during the flowering stage while MH are used during the vegetative stage. This is why Full Spectrum LED Grow Lights are the better option for your indoor grow room. With Full Spectrum LED Grow Lights there is no need to switch out your lights between vegetative and flowering stages. Many of the LED Grow Lights can be switched between stages with by selecting veg or bloom. Do your own research and reading to make sure you make the right decision for your grow room.


One of the hurdles that LED growers face is trying to equate their new, efficient lighting to systems and theories that were developed under traditional light sources. LED grow lights have very little in common with the sun, high pressure sodium, or fluorescent lighting. This misunderstanding has been amplified over the last two years by LED plant lighting companies marketing arrays using product descriptions such as "replaces 400 watts of HPS." This kind of statement is incredibly misleading and implies one can simply switch out an HPS with an LED array and expect the same results regardless of the application.​

There are LED grow lights on the market that claim to be 300 watts but only use 136 watts. How is this possible? Take a system that has 100 - 3 watt diodes. You would assume it is a 300 watt grow light. Since they are under driving the LED diode it only uses 136 watts at the wall. They do this for two reasons, one being it makes the diodes last longer and second it uses less power. In the HPS world a 250 watt bulb uses 250 watts. So you need to look at PAR ratings to compare LED vs HPS accurately.

PAR vs Lumens​

The total visible spectrum is perceived by us humans as white light, but the "white light" is actually separated into a spectrum of colors from violet to blue, to green, yellow, orange and red made up of different wavelengths. Plants use the blue to red part of the spectrum as their energy source for photosynthesis. The different combinations and the relative intensity of various wavelengths of light determines the CRI of a light source. Only part of solar radiation is used by plants for photosynthesis.


This active radiation Photo synthetically Active Radiation (PAR) contains the wavelengths between 400 and 700 nanometers and falls just within the visible spectrum (380 - 770nm). The light in this region is called PAR watts when measuring the total amount of energy emitted per second. PAR watts directly indicates how much light energy is available for plants to use in photosynthesis.


Lumen is the unit of total light output from a light source. The problem is that the various units - candela, candlepower, lumens, lux, foot-candle - get very confusing. Lumens is a measure of light flux, so is independent of the area. It is essentially the amount of light available. So think of a bright light. It has a fixed amount of lumens, regardless of how near or far you are from it.

The rhetoric has become so popular that growers have come to expect manufacturers to rate their led grow lights in the number of watts of HPS they replace. The fact is there is no scientific basis for a direct comparison to HPS. This isn't to say you can't replace HPS with LEDs- just that they are two completely different light sources with their own measurement variables and characteristics. Simply switching out the lighting systems will not give the same results. On that note, commercial growers, scientists, and educators basing their projects or utilizing methods developed through research under HPS or fluorescent lighting, should expect different results under LEDs.

The difference with the most profound effect would be temperature. The majority of research available on the effects of manipulating photoperiod or light intensity is based on a radiant (hot) light source such as HPS or the sun. Up to 80% of the light emitted from an HPS lamp is emitted as heat. With this in mind, HPS studies are not only manipulating the light, but manipulating temperature within the plant canopy. If you replace an HPS with a well made LED array you are able to provide more quality wavelengths but you have also eliminated the radiant heat by removing the HPS. It stands to reason that the outcome will not be the same.

LED Grow Lights for Your Cannabis garden?​

There are many benefits to using LEDs to grow cannabis indoors. In this article we will explore the difference between LEDs and HPS (High Pressure Sodium) bulbs.

LED grow lights have been getting a lot of hype in the recent years. This new technology is said to be much more efficient than other types of grow lights for multiple reasons. Firstly these lights save a lot of energy. LED's are light emitting diodes and these small, luminous lights show a lot of promise.

​The following are just some of the reasons why they have been gaining a following:

​Energy Efficiency

​They use energy much more efficiently than any other type of light meaning less power used. These lights, depending on the manufacturer, save as much as 40 - 75% on energy costs while producing the same amount of light.

​Long Life Span

These lights have a far longer life span than other bulbs, lasting as long as 50,000 to 100,000 hours compared to the 5,000 to 10,000 hour lifespan of high pressure sodium bulbs.

Less Heat​

Due to these lights efficient use of power they produce much less heat than other bulbs. The major benefit of this fact is that you will not need to use special fans and cooling equipment to keep your closet or small grow tent cannabis grow room cool. These are also less likely to burn your cannabis leaves. Another benefit is the reduced fire hazard.

LED's also do not need all of the accessories such as ballasts which other types of lights require.

Full Spectrum LED Grow Light

This is the most controversial point about LED grow lights. While many manufacturers will claim that their lights have the more optimum light spectrum many tests still contradict this major fact. The most important thing to note is that you get what you pay for. Cheap LED grow lights will produce less light while the more expensive ones can cost you a pretty penny. High-end LED grow lights have the ability to switch between veg and bloom stages. I would recommend using a full spectrum LED grow light that is rated in real wattage that can be switched between veg and bloom.

LED vs HPS Spectrum

The main reasons to use LED grow lights are the great ROI (return on investment) due to their low energy use and long life span. This technology is still developing rather quickly and you should do more research before deciding what type of grow light is best for your situation.

Conclusion: LED vs HPS

While an LED grow light won't "replace" an HPS much like the apple does not replace the orange, LED grow lights do provide a good alternative. By accepting the inherent differences between LED vs HPS we can overcome the confusion and start accepting LED grow lights on their own merits. Clearly, there is a significant difference between the two light sources. LED grow lights do exactly what they are meant to do which is supply full spectrum light, using very little energy, with a lifetime of 10-20 times longer than traditional light sources. This is a distinct advantage for LED grow lights.​


Hey I'm Dennis, Thanks for stopping by. I'm a Horticultural Expert in growing marijuana indoors and hydroponics. I will be sharing my expertise in growing marijuana with LED Grow lights.

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