Maximizing Yield [HPS vs LED Yield Explored]

Are you a passionate indoor gardener who’s been struggling with low yields? Trust me, I’ve been there. One of the biggest debates in the industry is HPS vs LED Yield.

It’s a question that’s been asked time and time again by growers just like you who are looking to optimize their gardens.

As a 25-year veteran of growing cannabis indoors, I know how frustrating it can be to put in all that effort and not see the results you’re hoping for.

In this article, we’ll dive into both types of grow lights and provide you with the information to make an informed decision for your garden.

Whether you’re a seasoned pro or starting out, we’ve got you covered.

So please sit back, relax, and let’s begin this journey toward higher yields!

What Is HPS?

HPS stands for High-Pressure Sodium. HPS lights are one type of high-intensity discharge (HID) grow lighting system and typically produce a higher light output than the other type, metal halide (MH).

Metal halide bulbs are ideal for vegetative growth, while HPS bulbs primarily support the flowering stage.

High-pressure sodium lights have long been the light of choice for indoor cannabis growers due to their reliability, efficiency, and cost-effectiveness.

Wattage choices for HPS lights range from as low as 75 watts all the way up to 4,000 watts, and their correlated color temperature is ideally suited for growing cannabis.

Budgeting growers can rest assured that these lights offer great value for money as they are cheaper than LED grow lights.

Growers hoping to cultivate a healthy, hearty cannabis harvest should consider using HPS lamps to take advantage of this type of light’s versatile benefits.

HPS and MH grow lights
Image sourced from Lift and Grow

Why I Should Use HPS Grow Lights

Whether seeking a reliable grow light with a proven track record for horticultural success or an efficient and cost-effective lighting solution, HPS grow lights offer many significant advantages.

As one of the oldest forms of horticultural lights, they provide a broad spectrum of light that boasts much higher output than LEDs.

Plus, they are much less expensive upfront than LEDs, making them economical when set up correctly.

Growers also appreciate their long safety record and standardized reliability across brands – in other words, there’s less variation in quality between different HPS grow light models.

Finally, sourcing and replacing parts are typically more accessible and affordable than LEDs.

Pros and Cons of HPS Lights

HPS grow lights are an excellent option for those who need to cover a large growing area without breaking the bank.

They do get pretty hot, though, so it’s crucial to have proper ventilation in place.

With a full spectrum, they can produce up to *1.8 grams per watt, but some growers find that they don’t quite match up to LEDs in cannabinoid and terpene production.

They require more maintenance than LEDs and have a shorter lifespan.

Still, if you’re an experienced grower looking for reliable performance, they could be well worth the investment.

grow room

Pros of HPS Lights

  • The upfront cost is much cheaper than LED grow lights.

  • Compared to LED lighting components and parts, HPS grow light replacements are more cost-effective and accessible.

  • HPS light manufacturers offer a more consistent quality standard between brands so you can shop confidently.

  • They are easier to place in larger grow rooms thanks to their wide-angle reflectors.

  • Revered as a benchmark among cannabis cultivators

  • ***Produce up to 1.8 grams per watt

  • If installed correctly, HPS systems are entirely safe to use.

  • Better light penetration

  • Full light spectrum

***Though some sources suggest that HPS lights produce a 0.5g/watt yield on average, from personal experience, I can attest to outputs ranging between 1.4 and 1.8 grams per watt with relative consistency!

Ultimately, genetic selection and climate are the deciding factors and the quality of the HPS fixture you choose.

I used the Gavita PRO 1000 with double-ended lamp technology to achieve these consistent yields.

hps grow light

Cons of HPS Lights

  • Generate copious amounts of heat, making it necessary to introduce a dependable ventilation system to prevent potential fire hazards.

  • Complex setup requirements can leave more room for errors, particularly for novice gardeners.

  • There is the potential for a decrease in the production of cannabinoids and terpenes compared to LEDs.

  • The intense heat generated may make this unsuitable for smaller grows.

  • Ballasts, timers, and exhaust fans must be configured appropriately for successful growth. This additional equipment can seem intimidating to new growers; however, the investment is worth it.

  • Far less efficient than LEDs

  • Unlike LED lights, which are relatively low-maintenance and long-lasting, HPS lights require significantly more upkeep to function correctly.

  • HPS lights have a shorter lifespan than LEDs, becoming dimmer and burning out more quickly.

What Is LED?

LED stands for Light Emitting Diode.

LED lights are an increasingly popular choice for gardeners and greenhouses as they offer energy-efficient lighting while providing the best environment for plants to thrive.

Utilizing LED technology, these fixtures contain a grid of hundreds to thousands of individual light-emitting diodes or chips which directly convert electricity into light.

Each diode produces a different color, and a broad or partial light spectrum can be created by blending them.

LEDs used for a grow room usually have a purplish hue from the mixture of red and blue diodes.

With LEDs, you can customize the light spectrum, which is key as many plants react differently depending on the colors they’re exposed to.

For instance, blue light is preferred in the vegetative stage, while red wavelengths dominate during bloom.

Allowing you to experiment with your setup, LED grow lights provide an economical yet effective way to ensure that your plants get what they need regarding light exposure.


Why I Should Use LED Grow Lights

LEDs have been making their way into regular lighting applications since they first came out. Still, their use in the cannabis space is relatively recent.

LED grow lights were quickly adopted by growers keen to experience more extensive growth and yields and enhanced potency with reduced running costs.

Unfortunately, lower-quality LED grow lights led to subpar results, and the reputation of LED lights suffered.

Thankfully, newer LED grow lights have improved considerably compared to their predecessors. They can now give HPS grow lights a run for their money when yielding plentiful cannabis harvests.

Quality LED grow lights can produce plants that rival those grown under traditional HPS lights – both in weight and potency.

However, there’s still one challenge with light-emitting diodes; not all LED grow lights are created equal!

So it’s essential to monitor the quality if looking for the best LED results.

Pros and Cons of LED Lights

confused man

LED grow lights offer more energy efficiency, lasting up to 100,000 hours without a ballast.

They offer the full spectrum or adjustable color temperature settings, and studies show they promote higher terpene and cannabinoid production.

The difference in the flower is starkly visible. The buds possess a notably higher concentration of trichomes.

However, quality LEDs can be pricey. Cheaper models may result in low yields, so investing in high-quality equipment is crucial if you go this route.

Pros of LED Lights

  • By replacing traditional HPS lights with LED fixtures, energy consumption can be reduced by an impressive 35% while achieving equivalent PPFD levels.

  • Designed to last an impressive 100,000 hours – that’s over 11 years of use!

  • Do not need to be connected to a ballast.

  • LED grow lights usually give the full range of light, or include switches to quickly switch from one color temperature to another for optimal plant growth during different stages.

  • ***Capable of producing up to 1.4 grams of bud per watt

  • Studies show LED lights encourage the production of higher terpene and cannabinoid concentrations.

  • LEDs are safe, easy to install, and dependable.

  • They don’t give off much heat.

  • Over time, their cost has decreased dramatically.

  • Perfect for adding additional PPFD to your grow light systems.

***While some sources suggest that the average yield is 1g/watt, I have observed outcomes of 1.4 up to 1.8 g/watt in my experiments – evidence of a significantly higher potential output!

Once again, genetic selection and climate are the deciding factors and the quality of the LED fixture you go with.

I went with the 1:1 Gavita CT 1930e LED fixture to achieve these yields, a marvel of technology.

led grow light

Cons of LED Lights

  • Inexpensive LED lights are vulnerable to malfunctioning, creating severe safety concerns.

  • The upfront cost of quality LEDs is up to 3 times more expensive than HPS lights.

  • Opting for cheaper models can often produce a subpar product with low returns.

  • Farmers cultivating large indoor spaces with multiple fixtures may find it difficult to justify the cost of setting up LED lighting systems.

  • As LEDs generate nearly no heat, indoor growers who reside in colder climates of the world or are tending to plants over winter may struggle with this consequence.

  • Compared to HPS lighting systems, LEDs are not uniform, and the variation in quality from one brand to another can be drastic.

  • Risks of photobleaching


hps vs led infographic

Key Factors To Consider For Top Yields

When it comes to producing top-notch cannabis, there is no one-size-fits-all approach; growers must consider a few key factors to ensure their harvests are of the highest quality and yield.

Choosing the right lighting system is essential – double-ended HPS or 1:1 replacement LEDs are often preferred – as is procuring the best available genetics since this can make a big difference in pest resistance and overall yields.

Climate control is instrumental in obtaining optimal growing conditions, as is accurate VPD (Vapor Pressure Deficit) monitoring, which offers insight into your plants’ transpiration rates and water loss.

Furthermore, pruning should be included as part of an ongoing maintenance regime to encourage healthy foliage growth, enabling increased yields in every flowering cycle.

Double-Ended HPS

When this technology first debuted, I was skeptical of the claims that growers were drastically increasing their yields.

That is until I decided to try it for myself and noticed a 50% increase in my yield!

This outcome can be credited to the 400V lamp’s impressive capabilities, producing 25% more light than traditional single-ended lamps while using the same amount of power.

Don’t waste your time with outdated single-ended fixtures.

1:1 Replacement LEDs

If achieving maximum yields and the highest terpene production is your goal, then the 1:1 replacement LED is your solution.

These LEDs can penetrate deep into your canopy at a light intensity comparable to an HPS – making them ideal for any grower’s needs.

Suppose you’re looking to build your grow room vertically with multiple levels.

In that case, a light bar configuration may be the best choice – however, keep in mind that yields will likely hover around half of what double-ended HPS or 1:1 LED replacements can produce.

Source Your Genetics

To guarantee strong yields, you must ensure that your plants’ genetics come from a reliable source.

Refrain from relying on cuttings or seeds from acquaintances – this could lead to poor quality and low harvests!

Invest in high-quality genetics for optimal results.

Remember that even with a subpar growing environment, you can still cultivate top-notch results when working with quality genetics.

For optimal, data-backed results, source your genetics from a nursery.

This will provide you with important information, such as yield and terpene expectations, that can guide your crop’s growth.

A few of my top performers sourced from nurseries:

  • Blackjack – 1.8g/watt

  • Strawberry Banana – 1.8g/watt

  • Dosilato – 1.6g/watt

  • Wedding Cake – 1.6g/watt

  • Cheetah Piss – 1.4g/watt

  • MAC1 – 1.4g/watt

  • Magic Melon – 1.5g/watt

  • Blue Dream – 1.3g/watt

The Importance Of Climate and VPD

After careful consideration of genetic selection, the climate is the second most critical factor for producing top yields.

To ensure maximum success, ensure your temperature and humidity levels meet optimal requirements.

Mastering the Vapor Pressure Deficit (VPD) is essential when setting parameters.

The bond between temperature and humidity requires precise calibration, making it an imperative component of environmental control.

Always refer to a VPD chart for the most effective results when designing your climate.

vpd chart
Image sourced from


When striving to achieve top yields, the lollypop technique is by far the most reliable way to prune your cannabis plants.

It increases airflow around them and eliminates any larfy material so that all of the plant’s energy goes directly into producing larger buds.

Whether you want bigger harvests or higher-quality buds – give this method a go and see what happens!

hps vs led yield

Frequently Asked Questions

What LED is equivalent to a 1000W HPS?

If you’re looking for the best yield possible, your ideal choice would be a one-to-one replacement.

In other words, expect a different result from a 600W LED fixture than you’d find with a 1000W HPS fixture.

In this case, the Gavita 1930e LED is an outstanding option – it has the comparable performance of that 1000-watt HPS but consumes only 780 watts!

Do plants flower faster under LED?

From my experience, I have witnessed that LED fixtures can shorten the flowering time of plants by up to a week, depending on the genetics.

How do you tell if grow lights are too strong?

Seeing signs of light burn or photobleaching on your plants is a surefire clue that the light intensity may be too strong; however, using a PAR meter to measure your PPFD(photosynthetic photon flux density), you can easily prevent these issues from occurring.

Can you veg and flower with LED?

Absolutely! That’s one of the benefits of using full-spectrum LEDs. 

To obtain the perfect environment for each growth stage, all that is necessary is to adjust the LED’s brightness using a PAR meter.

Bottom Line

In conclusion, HPS lighting is an excellent choice for anyone interested in setting up a garden indoors, given its affordable upfront cost, safety, light penetration, and full light spectrum.

Furthermore, it has become increasingly popular amongst commercial growers due to its consistent quality standard between brands.

On the other hand, LED lights are more efficient in electricity consumption, with the added bonus that it lasts significantly longer – up to 100,000 hours!

Although initially more expensive than HPS lighting systems, LED fixtures may be a better long-term investment as, over time, you can recoup the expense through energy savings. 

Additionally, they have been shown to encourage the production of higher terpene and cannabinoid concentrations.

In short, switching to LED grow lights could be well worth it in the long run.


Jesh is the founder of He was born in Stockholm, Sweden, and raised in the American South and the foothills of Northern California. He loves to grow all things, including as much of his own food as possible. He also loves to read and geek out on board games.

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