Review of The Best HPS Bulbs for Your Garden


HPS bulbs have been known as one of the most effective grow light for both outdoor and indoor beginning gardeners who are dreaming of consistent and big harvests. However, not all of them know very well about this technology.

Today article will provide you a complete understanding of HPS technology, an informative guide for you to buy best HPS bulbs and I will do an in-depth review of some popular products.

There is a wide range of products available on the market today, and below I have reviewed 5 of the very best options.

**Below, you will find more detailed reviews, but you can also click the links above to see current prices and read customer reviews on Amazon.

What does HPS light mean?

HPS is the abbreviation of the phrase ‘High-Pressure Sodium’ which is a light technology invented in 1964. It is popularly applied in the industrial lighting, particularly big manufacturing facilities as well as widely used as grow lights for plants.

An HPS bulb comprises an arc tube held by a shell in the bulb. To boost efficiency, they always keep the arc tube at a tremendously high pressure. Inside the tube, xenon, sodium, and mercury are often used to enhance the light spectrum.


The most popular way to kick off an HPS bulb is to start with a pulse. Through xenon gas, the arc will get started by that pulse, and then the lamp is turned sky blue. Next, the mercury, which is heated by the arc, will light up and provide a bluish color for your bulb.

Once the sodium begins to vaporize and your bulb gets hot, an arc will be forced to reach over 240 degrees Celsius (450 degrees Fahrenheit). A combination of sodium and other chemicals will be made to have a ‘white’ light. Likewise, the Mercury will add its blue light to the natural yellow spectrum.

Why are they so popular?

High Pressure Sodium technology is widely chosen due to the power of the light that will offer spectrum which could help your garden plants grow very well, especially for fruiting, blooming and flowering crops.

Plenty of different sizes are now available in the market, so you will have more opportunities to choose the most appropriate bulb for your garden. There are 150W and 250W bulbs, however, they always come with reflectors and ballasts in a kit.

Regarding bulbs, the most popular ones are 400, 600 and 1000 Watt. As a rule, the most popular is 400 Watt HPS bulbs, the most efficient is 600 Watt bulbs, and the hottest and most powerful is 1000 Watt bulbs.

Advantages and Disadvantages of HPS light

HPS technology has become popular thanks to its 5 main upsides, which are:

  • Bringing good spectrum to both fruiting and flowering

  • Reliable and affordable

  • High lumen productivity (from 80 to 160 lumens/watt)

  • Great PAR efficiency in comparison with fluorescent lights

  • The wide availability of different sizes of varied spaces

On the other hand, there are still some downsides that you should also consider before making a purchase:

  • They generate intense heat, and that is why they need to be cooled down

  • They often suffer from great degradation

  • They demand a reflector and ballast

High Pressure Sodium Spectrum Output

Each spectrum of light comes from one distinctive grow light. During the growing process, plants will respond to the spectrum of light that they get. Regarding science, this is called photomorphogenesis.

HPS bulbs shed the golden yellow light which is highly beneficial to boost flowering and budding production. HPS technology produces PAR spectrum which is the light from 400 to 700 nm, and it is necessary for the photosynthesis of your plants to take place.

HPS bulbs mostly generate usable light including red and yellow light, but sometimes infrared spectrum as contributing factor in heat production. To make the light spectrum balanced, gardeners often use Metal Halid lights as a supplement to the HPS light.

Ballast and why should you use it?

Without a matching ballast, you cannot use an HPS bulb, to be honest, because, you are breaking the bulb and in the worst situation, there will be an explosion. So what is a ballast and why is it important?

A ballast is equipment that supplies your HPS bulbs with energy. The electrical current and input voltage will be taken and regulated into pulses by the ballast. As a result, your bulb will operate efficiently and in the ideal status.

Which one is the right wattage for your garden?

Based on the size of your garden, you should choose the lighting it needs. Sometimes, it will make you very confused to find out how much you light your plants need. But do not worry! I will give you some information to decide which HPS bulb fit could your garden best.

150 Watt

In fact, the majority of 150 Watt grow light bulbs often go with their built-in reflector and ballast. This kind of bulb does not produce much heat in comparison with other sizes. However, the least effective bulb is also 150 Watt among all High Pressure Sodium bulbs.

Hence, the recommended plant distance is about 6 or 15 inches as an absolute minimum away from the canopy. Likewise, the suggested area is 0.45m x 0.45m or 1.5-inch x 1.5 inches.

250 Watt

Similarly, the majority of 250 Watt grow light bulbs often go with their built-in reflector and ballast. In spite of the fact that it is not difficult to buy a 250 Watt bulb at the store, it is pretty tough to look for a dependable stand-alone 250 Watt ballast.

Additionally, 250W bulbs get hot greatly while operating, do not forget to step up the cooling system that will help your plants stay healthy. The good plant distance is 10 inches or 24cm as a minimum from the capony, and 0.75m x 0.75m is the suggested area.

400 Watt

It will begin to be productive with 400 Watt bulbs, although they will produce much heat. HPS bulbs at 400 Watt nearly reach the top of HPS efficiency that will not only shed a great deal of PAR light but also generate intense heat at the same time.

The recommended plant distance is about 14 inches or 30 cm as an absolute minimum away from the canopy. Likewise, the suggested area is 3.5’’ x 3.5’’ or 1.1m x 1.1m.

600 Watt

In general, a 600W bulb could produce approximately 90,000 to 150,000 lumens/watt. Hence, these are considered to be the effective bulb among all sizes. In other words, the greatest deal of electricity will be converted into what we call ‘usable light’ by 600W bulbs.

Also, these bulbs could help you minimize unnecessary waste. The recommended plant distance is about 18 inches or 45 cm as an absolute minimum away from the canopy. Likewise, the suggested area is 4.5 inches x 4.5 inches or 1.4m x 1.4m.

1000 Watt

As I mentioned above, 1000W bulbs are less productive than 600W bulbs, but they are more effective than 250W ones. Honestly, you should try two 600W bulbs for your developing garden before purchasing a 1000W bulb.

The recommended plant distance is about 24 inches or 60 cm as an absolute minimum away from the canopy. Likewise, the suggested area is 6 inches x 6 inches or 1.8m x 1.8m.

Double-ended bulbs

This is the latest model of HPS bulbs. According to research, they are at least 10 percent more productive in producing usable PAR light for plants. Apart from that, a longer lifespan is another plus point for DE bulbs.

However, the double-ended bulbs will produce more infrared as well as ultraviolet light than traditional ones.

Product Reviews – The Best HPS Buld

1. EyeHortilux 1000 Watt HPS Grow Bulb

This product is a traditional High Pressure Sodium grow bulb that is suitable for indoor gardens like greenhouse kit. The difference here is that the manufacturer supplements Dual Arc to the HPS lights instead of using Metal Halide as usual.

Apart from containing less mercury than normal HPS bulbs, the bulb from EyeHortilux is easy to get broken, so it does not have a long lifespan. One annoying thing is the new product often looks like getting used or damaged.


  • A good balance of frequency, lumens, power, and spectrum
  • Reasonable price
  • Great design
  • Consists of less mercury


  • Often looks like getting used or damaged
  • Easy to get broken or scratched
  • The brightness is not good as expected
  • Generate much heat

2. Plantmax 400W HPS Bulb

This HPS from Plantmax could produce at least 50,000 lumens per watt. More than that, 24,000 hours is the lifespan of this product that could satisfy all gardeners. Also, Plantmax HPS bulbs were tested by American National Standards Institute.

However, as I said above, 400W bulbs is not as efficient as other 600W HPS bulbs because they do not produce usable lights as many as 600W or 1000W HPS bulbs.


  • Reasonable price
  • Great design and packaging
  • Beneficial for vegetables as the plants grow beautifully
  • Excellent customer services
  • Tested by American National Standards Institute


  • Does not generate PAR spectrum as much as other 600W or 1000W bulbs
  • Generate much heat

3. Sylvania 400 Watt HPS Bulb

Silimar to Plantmax bulb, this HPS bulb from Sylvania could last for 24,000 hours and produce 50,000 lumens per watt. The color temperature, as manufacturer announced, is about 2100 kelvins or 2100 degrees Celcius.

With 2100 degrees Celcius, you could imagine how hot it is so this is the most significant downside of this product. As I recommended, you should step up your cooling system to protect your plants.


  • Reasonable price
  • Great design and packaging
  • Beneficial for flowering and fruiting as the plants grow beautifully
  • Excellent customer services
  • Good brand reputation


  • Does not generate PAR spectrum as much as other 600W or 1000W bulbs
  • Generate much heat

4. Philips 600W HPS Bulb

As I introduced, 600W bulbs are considered as the most effective HPS bulb which combines the advantages of 400W and 1000W HPS bulbs. This product from Philips provide you with high lumens and safeguard your crop quantity and quality as well.

The robust and simple construction was made to prolong its lifespan and increase the reliability. The biggest disadvantage of this bulb is that it is only compatible with the 230V fixture.


  • Great design to improve your crops and its reliability
  • High lumens
  • Safeguards your crop
  • Does not require battery to operate
  • Beneficial for flowering, budding and fruiting production
  • Reasonable price


  • Compatible with the 230V fixture only

5. Ushio Double Ended 1000W HPS Bulb

To achieve a high photosynthesis efficiency, this product is equipped with high blue and red spectrum. Also, it has a long lifespan with low energy requirement and high lumen production.

Although double ended HPS bulbs are more productive than traditional bulbs and could help you avoid unnecessary wastes, they generate more infrared and ultraviolet lights than usual bulbs do.


  • On point spectrum
  • High lumen
  • Long lifespan
  • Energy saving
  • Good photosynthesis efficiency
  • ISO9001 certified


  • High price
  • Create more infrared and ultraviolet lights which are harmful to your plants

Choosing the Best HPS Bulbs for Your Garden

In short, high-pressure sodium technology is a good idea if you want to be outdoor or indoor gardeners. There are 4 main types of HPS bulbs, so check your area to choose the best HPS bulb for your lovely garden, and a 600W bulb is always my top priority.

I hope that you greatly enjoyed this post and found it useful. If you have any questions or other interesting tips, leave a comment to let me know. Last but not least, do not forget to like and share this post with people who are interested in this topic.

James G. Craig

James G. Craig is a gardening enthusiast who splits his spare time between growing vegetables, preening his flower gardens, and blogging about his experiences at the Gardener Corner.

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