More home growers are taking advantage of affordable propagators and grow lights to extend the season and improve yields. But which horticultural lighting system is best for the individual grower?
Two popular lighting options are T5 fluorescent lights and LED systems. Each has its strengths and weaknesses, making them suitable for different applications and grower preferences. Below is a detailed comparison of T5 fluorescent and LED systems, focusing on key aspects such as efficiency, light spectrum, lifespan, heat output, and cost.
Propagator with T5 fluorescent horticultural grow lights.
Light Spectrum
T5 Fluorescent Lights
Spectrum
T5 fluorescents offer a broad spectrum of light, closely mimicking natural sunlight. They are available in various colour temperatures, with options for cool white (5000-6500K) ideal for vegetative growth and warm white (2700-3000K) for flowering.
Customization
Limited ability to customize the light spectrum. Growers often need to choose specific bulbs to meet the plants’ needs at different growth stages.
LED Systems
Spectrum
LEDs provide a highly customizable light spectrum. Modern LED grow lights can be tailored to emit specific wavelengths that plants require for photosynthesis, such as blue light for vegetative growth and red light for flowering.
Customization
High degree of customization, making it possible for growers to adjust the spectrum dynamically to optimize plant growth throughout different stages.
Energy Efficiency
T5 Fluorescent Lights
Efficiency
T5 fluorescents are more energy-efficient than older fluorescent technologies but still consume more power compared to LEDs. Generally T5 fluorescent bulbs use 30 to 40% more electricity to deliver a given amount of light than LED systems.
Power Consumption
Generally, T5 systems consume about 40-60 watts per bulb.
LED Systems
Efficiency
LEDs are known for their superior energy efficiency, converting a higher percentage of electricity into usable light for plants.
Power Consumption
LEDs consume significantly less power, with some high-quality systems using as little as 20-30 watts to produce the same light output as T5 fluorescents of 40 – 60 watts.
Power Consumption Note
Home growers are most often using grow lights in combination with a thermostatically controlled heated propagator. The additional heat produced by T5 fluorescent lights is utilised by the propagator so effectively there is no additional running cost.
LED Grow Lights over potato plants on the ISS – Photo NASA
Lifespan
T5 Fluorescent Lights Lifespan
Typically T5 Bulbs last around 10,000 to 20,000 hours, depending on the brand and usage. Over time, their light output diminishes, requiring replacement. More frequent replacement can increase long-term costs and maintenance efforts.
LED Horticultural Lighting Lifespan
LEDs have a much longer lifespan, often exceeding 50,000 hours. They maintain their light output more consistently over time. However, LEDs are reliant on electronics to reduce voltage and control them. With cheap LED horticultural lighting systems the electronics tend to fail before the LEDs. Sometimes they fail very quickly. In that event, the entire fitting will require replacement.
Heat Output
T5 Fluorescent Lights
Heat Production
T5 lights produce moderate heat, which can be beneficial in colder environments but may require additional cooling in warmer settings.
Heat Management
Growers may need to manage heat output to prevent overheating, which can stress plants.
LED Systems
Heat Production
LEDs generate very little heat compared to T5 fluorescents. This reduced heat output minimizes the need for additional cooling systems in warm environments and reduces the risk of heat stress on plants.
Heat Management
Less heat simplifies environmental control, especially in enclosed growing spaces.
Grow Light Cost
T5 Fluorescent Lights
Initial Cost
Generally, T5 fluorescent systems have a lower upfront cost compared to LEDs, making them an attractive option for beginners or small-scale operations.
Long-term Cost
Higher energy consumption and more frequent bulb replacements can lead to increased long-term costs. However, with a T5 lifespan of say 15,000 hours being used with a propagator for at most 1,000 hours per annum, it is unlikely to be worth considering.
LED Systems
Initial Cost
LEDs have a higher initial cost, which can be a barrier for some growers. However, this cost is somewhat offset by their efficiency and longevity. This assumes a good quality LED system is purchased.
Long-term Cost
Lower energy bills and fewer replacements can result in significant savings over time, making LEDs more cost-effective in the long run.
Comparing Grow Lights – Application Suitability
T5 Fluorescent Lights
Best For
Seedlings, cuttings, and low-light plants. Their broad spectrum and moderate heat output are suitable for early plant development and small-scale operations.
Limitations
Less effective for plants requiring high-light levels and large-scale commercial operations due to higher energy consumption and lower light intensity.
LED Systems
Best For
All stages of plant growth, from seedlings to flowering and fruiting plants. Ideal for both small-scale and large-scale operations due to their customizable spectrum, energy efficiency, and low heat output.
Flexibility
LEDs are highly versatile, making them suitable for a wide range of horticultural applications, including indoor farms, vertical farming, and greenhouses.
Summary – Comparing Grow Lights
Both T5 fluorescent lights and LED systems have their unique advantages and disadvantages, making them suitable for different horticultural needs. T5 fluorescents offer a broad spectrum of light with moderate heat output and lower initial costs, making them a good choice for beginners and specific applications like seedling propagation. However, they fall short in energy efficiency and lifespan compared to LEDs.
LED systems, on the other hand, provide superior energy efficiency, customizable light spectra, longer lifespan, and lower heat output, making them ideal for a wide range of horticultural applications. Although they come with a higher initial cost, the long-term savings and flexibility they offer make them a worthwhile investment for serious growers.
Choosing between T5 fluorescent and LED systems ultimately depends on the specific requirements of the growing operation, budget, and long-term goals. For those seeking to maximize efficiency, yield, and quality, LED systems are the clear winner. However, for smaller-scale or budget-conscious growing, T5 fluorescents can still provide effective and reliable lighting solutions.
Personally, as a small scale home grower who uses grow lights in conjunction with a thermostatically controlled propagator for a limited period early in the growing season, T5 fluorescents are the optimum choice for my horticultural lighting needs. Your needs may differ and hopefully the information above will enable you to make the best decision for you when comparing grow lights
Further Information
- Full Spectrum Light – Grow Lighting using LED
- Horticultural Lighting: Illuminating the Path to Plant Growth
- Why are LED Horticultural Grow Lights Purple?
