LED Grow Lights: Can You Use Any Light Source?

Written by Linus Li


Posted on June 14 2023


  1. Introduction
  2. LED Grow Lights
  3. Other Light Options
  4. Limitations of Other Light Sources
  5. Factors to Consider for Plant Growth
  6. Conclusion


Of Course NOT!

Many light sources are used for growing indoor plants, from fluorescent tubes to high-pressure sodium lamps. However, LED grow lights have emerged as the optimal option given their higher efficiency, customizable spectrum, and long lifespan. By focusing on LED grow lights, this article evaluates their suitability for plant growth compared to other light sources and the factors to consider for optimal plant performance. 

grow light

LED Grow Lights

LED grow lights consist of small, individual LED chips that produce focused beams of light in specific wavelengths. Their key advantages over traditional light sources for indoor plant growth include the following:

Higher Efficiency

LEDs convert up to 90% of the consumed energy into light, making them much more efficient than fluorescent or HPS bulbs which waste a large portion of heat. This drastically reduces energy costs. The higher efficiency translates directly to higher light intensities for the same power input, enabling greater plant photosynthesis and growth rates.

Customizable Spectrum

LEDs allow precise tuning of the light spectrum by mixing different colors of chips. Growers can select light recipes optimized for the specific plant's photosynthesis needs at different growth stages. The ability to supplement blue light for vegetative growth and red light for flowering ensures plants receive what they require for maximum performance.

Long Lifespan

LED grow lights last 50,000 to 100,000 hours, which is around 10 to 20 times more than traditional bulbs. This translates to less frequent replacement and reduced long-term costs. The longevity and lack of bulb replacements also make LEDs more sustainable due to less electronic waste. The stable light output over the lifespan further ensures consistent growing conditions without performance drop-offs like HPS and fluorescent bulbs.


Most LED grow lights are fully dimmable, allowing growers to adjust light intensity levels as plants' needs change. This added flexibility optimizes plant health and yields by more closely mimicking natural conditions compared to the fixed output of other lighting types.

The key attributes of LED grow lights - high efficiency, customizable spectrum, longevity, and control - combine to offer unprecedented performance for optimized plant growth. 

grow light

Other Light Options

Fluorescent tubes and high-pressure sodium lamps have some drawbacks for plant growth compared to LED lights:

Fluorescent Tubes

Lower Efficiency

The low efficiency of 35-50% means that half to two-thirds of the energy consumed is lost as waste heat. This excess heat can raise grow room temperature and increases cooling demands. The higher operating costs of running fluorescent tubes for the same light output can outweigh their lower initial purchase price compared to LEDs with up to 90% efficiency.

Require External Ballast

The external ballast required to operate fluorescent tubes increases both the upfront cost and complexity of installation. An additional device that can take up space, produce heat, and fail over time makes fluorescent fixtures more expensive and troublesome compared to the simplistic design of standalone LED grow lights.

High-Pressure Sodium Lamps

Higher Heat Output

The high level of waste heat production from 60-70% of energy input raises grow room temperatures and results in higher cooling systems and energy costs. This excess heat also shortens bulb lifespan, requiring more frequent and costly replacement compared to cooler-running LEDs.

Limited Light Spectrum

The predominant yellow-orange spectral output lacks the beneficial blue and red wavelengths that many plants require. This restricted spectrum limits the suitability of high-pressure sodium lamps for different plant varieties and often results in inferior growth compared to the tailorable light spectrum of LED grow lights.

Overall, the advantages of LED grow lights in efficiency, tunable spectrum, and controllability make them the technology of choice for controlled-environment agriculture moving forward. With the growing global demand for food, LED lights will play a pivotal role in boosting agricultural productivity in a sustainable way for years to come.

Limitations of Other Light Sources

Other traditional light sources exhibit several limitations for indoor plant growth compared to LED grow lights:

Inadequate Light Spectrum

Fluorescent tubes and high-pressure sodium lamps emit a restricted range of wavelengths, lacking certain frequencies of light required by plants for optimal photosynthesis and growth.

Shorter Lifespan

The low efficacy of these light sources leads to premature failure, with fluorescent tubes lasting around 8,000-20,000 hours and HPS bulbs lasting only 8,000-24,000 hours. This is much shorter than the 50,000-100,000 hour lifespan of LED lights.

Lower Light Intensity

Due to their lower efficacy and higher heat output, fluorescent and HPS lights produce less usable light per watt than LEDs, resulting in a lower intensity of illumination for plants.

Higher Energy Consumption

The low efficiency of fluorescent and HPS lights means they consume significantly more energy to produce the same amount of usable light as LED grow lights. This drives up operating costs.

The key limitations of non-LED light sources - including inadequate spectrum, short lifespan, lower intensity, and higher energy use - demonstrate that they fail to provide the optimal performance needed for precise plant growth. As a result, LED grow lights have emerged as the superior option for indoor horticulture.

Factors to Consider for Plant Growth

Several factors must be considered to determine the optimal light source for plant growth:

Light Intensity

The brightness or flux of light, measured in lumens or micromoles per second, impacts photosynthesis rates and ultimately influences plant growth. LED lights can be tailored to provide the precise intensity needed.

Light Spectrum

The distribution of wavelengths within the light, measured in nanometers, determines if a light source matches the absorption spectrum required by a plant. LEDs offer the greatest spectrum control.


The duration of the daily light cycle that a plant receives affects processes like flowering and ripening. LED lights enable precise scheduling of photoperiods.

In summary, optimal plant growth depends on having a light source that can be tailored to deliver the right intensity, spectrum, and photoperiod for a particular plant's needs. LED grow lights, with their high level of customization and control, are best suited to meet these requirements.


Though other light sources can work for some plants, LED grow lights have emerged as the optimal solution for most indoor crops due to their higher efficiency, longer lifespan, and ability to precisely deliver the intensity, spectrum, and photoperiod required to maximize plant health and productivity. As a result, LEDs have become the industry standard for horticulture seeking optimal growth.

Read More



Leave a Comment