Switching HPS to LED Grow Light. What to Consider?


There are many reasons why growers prefer to use LED growing lights today. It is for these reasons most people are switching from MH and HPS lights at a rapid rate. Some of these reasons include longer lifespan, reduced heat generation, increased energy savings, and spectral efficiencies.

While there are many benefits to using LEDs over HPS grow lights, there are many other factors a grower must consider before making the switch. It's no longer news that LEDs cost far more than HPS luminaires. So, it is imperative to effectively manage costs and have successful growth with LEDs.

Difference between LED and HPS

Every grower wants to optimize yields ad output every year. The quest to get better comes with a couple of considerations e.g., the choice of grow lights. Being able to optimize crop production, and have maximum operational control comes only by having a system that provides and guarantees such. This is why having a successful LED growth strategy supersedes other lighting systems generally.

Here are a few differences between LED growing lights and HPS lights:

Less Heat; More Light

There’s a reason why dimmable grow lights have become popular over time. This is because of how they put power in the hands of growers to regulate radiance and heat. One thing every grower must settle in their minds is how to grow their crops using LED lighting systems. Comparing HPS and LED lighting, the difference is in their science, especially in how they convert electricity to heat energy.

Under the same conditions, LED molecules tend to generate more light and less heat compared to those of HPS. This signals that there's a need to revisit former growth strategies to have the best yields.


Here’s the simple trick, the greater the heat generated, the lesser the humidity. Like every other electronic device, LED growth lights can produce heat. The mistake most growers make is to try to compare LEDs to HPS in terms of wattage. Transitioning from HPS to LED grow lights must be done with the requisite information. For instance, you don't expect to suddenly overcome the challenge of heat production when you use the same LED wattage as you previously used for HPS lights.

In basic terms, humidity is the level of water vapor found in the air. So, it is impossible to have some of this water vapor stay in your plant’s environment in the face of elevated temperatures associated with electronic lighting systems.

However, a big difference between HPS and LEDs is that with the right information, growers can regulate the temperature and radiance that gets to the plants. It has also been found that LEDs generally produce less heat and are associated with better humidity levels.

Correct distance

Another difference between LED growing lights and HPS lights is the distance they should be placed from your plants. Generally, it is recommended that you should not go beyond a distance of 12 inches while hanging your HPS lights from your plants. HPS lights tend to lose their potency at this distance. So, it becomes pointless to use them for indoor growing.

However, the best grow tent lights remain LEDs as they can be used at a distance of 24-36 inches without losing their potency or drying off the plants with radiant heat. LEDs help to nurture plants at all stages, especially at the crucial stage where maximum support is needed for them to thrive. The drawback is that if they are too close to plants, they could trigger more sprawling growth, damage the plants, or produce abnormally broader plants.

Do LED Grow Lights Yield More Than HPS Grow Lights?

From HID Bulb to LED Chip

The comparison between HPS lights and LED grow lights has remained an age-long debate. Initially, LEDs lacked intensity, were not cost-effective, and never had the optimal light spectrum for growing plants. So, HPS remained the favored choice by most growers.

Today, LED technology has metamorphosed, and this has changed the tides. In terms of delivering all the needed light spectra for plant growth and development, LEDs both meet and exceed plant requirements. In the long run, LEDs save costs by using less electricity and cutting down cooling costs. The chances that growers will get rebates are much higher with LED technology than with HPS.

All these factors (performance, efficiency, and cost) make LEDs a much better option.

Lesser Costs; More Yields

The cost of operating a grow yard or garden revolves around

  • Electricity costs
  • Air conditioning/ Cooling
  • Maintenance costs

Electricity Costs

When compared to HPS grow lights, LEDs have much better efficiency. LEDs use lesser watts to get the same output compared to HPS. LED growing lights subsidize the total amp average while helping growers to save money on electricity bills. This also allows you to acquire more grow lights within your facility without the need to upgrade your system.

Air Conditioning Costs

Generally, LED growing lights give off less heat than HPS lighting systems and are passively cooled. In hotter climes, AC is usually deployed to cool down the lighting system. So, that'd mean more AC costs if you use HPS lights. In cooler climes with LEDs, you also get to use a centralized heating system, not necessarily looking to HPS lamps for heat (which isn’t controlled or consistent).

Maintenance Costs

HPS lamps have a much shorter life expectancy than LED grow lights. On average, LEDs can last up to 50,000 hours – equivalent to 10 years of use. This is much better than HPS where you need to start charging after about 8-12 months. Yearly, you may need to replace about $60-100 bulbs; this, combined with the labor involved, plus the fact that it is a recurring cost that adds up eventually, is a discouraging factor.

Reasons Why Farmers are Switching to LEDs

In the previous sections of this article, one factor that has consistently stood out has been efficiency and cost as major differences between HPS and LED grow lamps. The first question every farmer must answer is this, “do grow lights work?” then, they will proceed to ask for the best grow lights to meet their needs and expectations. We have proven that LEDs are more advantageous than HPS lamps.

Let’s look at a few reasons why farmers are switching to LEDs today.

Adjustable full spectrum and consistent light intensity

There are light spectrums that trigger growth and help plant development. The demerit of most grow lights is that they may have one spectrum and many others that aren't necessary for plant growth. In all, what makes a good grow light is its ability to provide the ideal light spectrum to stimulate plant growth.

[PAR map of Mini Sun-2(150 Watts Version)]

In horticulture, intensity is king. The light must be adequate to support growth and development.

All these features are included in the LED grow light system. LEDs have outshined single-ended HPS grow lights in this regard.

Investment to reduce costs over time

No one wants to spend outrageous amounts of money on growing their plants. Especially when these costs are unnecessary and can be avoided. LEDs have fewer maintenance costs, more efficiency, and less likelihood to break your pocket. This is why farmers are now migrating to use LED growing lights as it stands to be a profitable investment in the long run.

Other Common Questions

What grow lights does NASA use?

"NASA has done several experiments with growing plants in orbit on the space station. The Veggie system uses LEDs to provide the kind of light that plants need."
Image Source:NASA

NASA uses LEDs in space stations to grow plants. They use it for its efficiency, less energy consumption, and heat generation. These lamps use specific wavelengths to stimulate biological reactions in plants. Plants on board don't need to manage human biorhythms; instead, they are tuned to the frequency needed to support plant metabolism.

Are LEDs brighter than HPS?

In terms of lumens per watt, HPS and LEDs have an undisputable similarity. LEDs generate 37-120 lumens/watt. While HPS gives off a range of 40-150 lumens/watt. However, due to the omnidirectional challenge that most HPS lamps have, LEDs are perceived to be much brighter.

What lights do professional growers use?

Professional growers prefer to use LED grow lights for many reasons ranging from ease of use, efficiency, and yield to cost and maintenance. The wide array of light spectra that LEDs have makes them an easy pick. To crown it all, LEDs put the power in the hands of the grower to adjust the intensity to meet a certain requirement. Most professional growers have the intent of crop yield and revenue at the back of their minds when selecting a grow light. LEDs have always helped plants thrive at the growing stage, giving rise to healthy adult plants.


LEDs will always trump HPS in all comparisons and debates for the obvious features and upgrades made over the years. Patterning after leaders in the horticulture industry is sure to guarantee you a successful growing regime. One of the open secrets used by professionals and experts is LED growing lights. They minimize cost and always have high yields of produce.

Are you considering LED grow lights for your plants? Start here.