When growing indoors, you have a lot to think about. There’s humidity, temperature, soil, etc. – and this can be even more complicated if you’re working with hydroponics. One of the most significant considerations is your grow light, and indoor growers always ask about T5 vs. LED grow lights. In this article, we’re looking at the differences between these two options, so you can decide what’s best for your indoor garden.
We should point out that the debate between these two types of lights rages on, but the good news is that there’s still plenty of space for both LED and T5 bulbs. We’ll lay out opportunities for using both of these two options.
Factors To Consider When Purchasing A Grow Light
There is a wide range of light qualities out there. Below are the primary considerations for indoor growing.
- Initial cost – the cost of the bulb, the fixture, the setup, and accessories
- longevity – how long the bulb lasts
- life-time cost – the overall cost of purchasing and running the bulb, as well as longevity and quality of the light
- energy efficiency – the amount of energy used to run the fixture and light
- color temperature – whether blue light, red light, or anything else on the spectrum, we’re looking at which options make the most sense for your situation
- light output – the amount of light produced
- light received – the amount of light that the plant can absorb
Why Is Comparing Grow Lights Difficult?
Grow light companies, and distributors use a lot of fluffy language to market their products. You’ll see words like lumens and light intensity used, as well as acronyms like PAR, PPF, and PPFD.
Here’s what some of these definitions and acronyms mean:
PAR Vs. Lumens
It’s easy to overlook the fact that plants and humans have incredibly different perceptions of light. Humans use photopic vision to sense color, which is measured in lumens. Photosynthetic active radiation (PAR) is the light wavelengths that drive photosynthesis in plants.
PPF: Intensity Of Light
PPF (Photosynthetic Photon Flux) refers to the total amount of light produced per second by an LED, T5 bulb, or other light sources. This is what we refer to as the intensity of the grow light. The unit of measurement is micromoles per second (umol/s).
PPFD: Measurement Of Light Received
The photosynthetic photon flux density (PPFD) is used to measure the quantity of PAR that travels from your fixture to your plants. In other words, this is a measurement of the PAR emitted by the lighting fixture at the plant.
What Are The Different Types Of Light Available?
There are several grow lighting options, but they are typically divided into a few different categories.
Ceramic Metal Halide Lights
This option is under the high-intensity discharge umbrella and creates light when an electric current passes through metal halide gas and mercury. It is known for having a high-quality light emission 3-5 times more efficient than incandescent lights. That said, they take a long time to heat up, meaning you won’t have your light immediately, as in the case of options like LEDs.
High-Pressure Sodium Lights
For a long time, HPS systems were the industry standard because they were cheaper, had a higher intensity, and produced a lot of red light.
They also emit a lot of yellow light, which is why they’re widely used for street and security lighting. For many years, HPS lights were preferred by indoor and greenhouse growers because of their large outputs and broad color spectrum.
This is the old-timey option that requires electricity to run through a filament, heating it and producing light. This is the one you can thank Edison and Swan for making.
For anyone reading at home, you probably don’t need an incandescent grow light. There’s still plenty of healthy debate between which lighting is best for indoor growing, but I don’t know of anyone who still thinks incandescent lights are a viable option. And while products under the LED umbrella improve every year, the incandescent light is just flickering into obscurity.
Fluorescent Grow Lights
Fluorescent lighting is an umbrella category over CFLs, linear fluorescent tubes, T5 bulbs, T8 bulbs, T12 bulbs, etc. This versatile lighting option is used in stores, schools, offices – and sometimes indoor gardens. To produce light, electricity enters the fluorescent fixtures through a ballast, feeding into the metal pins on both ends of the fixture. As the electricity flows through the tube, the gasses start reacting and producing light visible to the human eye. Fluorescent lights are cheap to purchase, pretty compact, and more efficient than incandescent bulbs. T5s are specifically known for seed starting.
LED Grow Lights
LEDs are the up-and-coming stars of the grow light world. They’re practical, energy-efficient, and becoming more affordable by the year. LED lights are made up of two semiconductor materials, one charged positively (protons) and the other negatively (holes) (electrons). When these two particles collide, energy in the form of a photon is emitted. The quantity of energy released determines the color of the light. After that, the light is focused and emitted in a specific direction. LEDs are known for producing a lot of light, specifically full-spectrum light.
Want to see how LEDs compare? Check out our LED Grow Lights Vs. HPS article here.
LED Grow Lights Vs. T5s: An Overview
Okay, now that we’ve given you the basics, let’s dive into these specific options, go through their definitions, lay out their pros and cons, and then compare them. We’ll start with LEDs.
LED Grow Lights
What Is An LED Light?
The term LED refers to a light-emitting diode. LED grow lights are energy-efficient luminaires that produce light for growing plants. LED fixtures function by combining two semiconductor materials. Energy is released as a photon when these two particles collide. The hue of the light depends on how much energy is released.
There’s a genuine chance that we will all end up using LEDs for all of our lighting needs, indoor growing and otherwise. If we all used LEDs in the United States, it would drop the lighting energy needs by at least 75%.
Benefits Of LED Lamp
There are almost too many benefits to count with these indoor grow lights. Even with the higher price tag, LED light sources make the most sense in the long run.
- they produce less heat than other lighting options
- most grow light LEDs allow you to customize the amount of light emitted
- they produce full-spectrum light (light that’s similar in spectrum to natural sunlight)
- they’re becoming more and more affordable
- they’re more compact than most growing options
- they have a significantly longer lifespan than most other options
- there are sometimes government rebates available for using LEDs over alternatives
In terms of light sources, LEDs are one of the best choices for indoor plants. Here are some of the best options for in-home growers.
Indoor plant guide: Philodendron Gloriosum: The Complete Growers Guide
LED Best Seller List By Value
T5 Grow Lights
What Are T5 Lights?
T5s are a type of fluorescent grow light, meaning they’re composed of a glass tube containing argon and mercury vapor. With this grow light system, metal electrodes are coated with an alkaline earth oxide that emits electrons at both ends.
When the current passes between the electrodes, the gas between them becomes ionized and emits UV light. The inside of the tube is covered with phosphorus, a material that absorbs UV rays and fluoresces. As a result, the energy is released in the form of visible light.
T5s and other fluorescent options are typically less expensive alternatives to LEDs and are cooler and more efficient than incandescent lamps.
What Does T5 Mean?
The letter “T” in T5 refers to the lamp’s shape. The number after the “T” usually denotes the fluorescent tube’s diameter in eighths of an inch. For instance, T5 lights have a diameter of 5/8 inch. A T8 bulb is 8/8″ or one inch in diameter, and a T12 is 12/8″ or 1.5″ in diameter.
The benefit of a T5 is that, while 40% smaller than a T8, it can produce a similar amount of light. And they are typically considered more efficient. So if you go with a T5 option, you’ll have to buy fewer grow lights, and can save costs.
How High Should I Hang My T5 Grow Lights?
Since T5s don’t generate as much heat as other options, some growers think you can place them as close to your seedlings as you’d like. Instead, you should put your lights about 10″ above the plants in most cases, as this optimizes the amount of light received.
T5 Grow Lights: Best Choice
There are many T5 options out there, but here are a few options to get you started.
Benefits Of T5s
- they produce relatively little heat, especially next to HID or other fluorescent bulbs
- they Last 10x longer than incandescent bulbs
- ideal for seedlings and cuttings
- suitable for a variety of herbs and vegetables
- good for aquariums
Cons Of T5s
- In many cases, you will need several types of bulbs to simulate natural sunlight. Blue lights are ideal for vegetative growth, while red lights work better for flowering plants. If you’re willing to invest in the more expensive multi-spectrum T5 bulbs, this can improve your harvests and limit the amount of bulb-changing you need to do
- less energy-efficient than LEDs
- the bulbs can be hazardous to human health if broken
Must-read flowering plant guide: Growing Lavender Plants Indoors
Are T5 Lights Good For Growing?
Of the fluorescent lighting options, T5s are my favorite for growing seedlings and small plants. They produce significant light that’s good for vegetative growth, and they don’t generate much heat. They’re also a more affordable option than most LED alternatives.
Do T5 Grow Lights Use A Lot Of Electricity?
Compared to other fluorescent lights, T5 bulbs are more efficient and therefore use less electricity. This is also true for most HID and incandescent light sources.
Differences Between T5 And T8 Bulbs
The main difference between the T5 and T8 Grow Lights is the diameter of the fluorescent tubes. T5s are 5/8″ in diameter, while T8s are 1″ in diameter. Also, T5s are slightly shorter than T8 fluorescent tubes. This is an important note as it means it could be difficult to swap out T5s and T8s on the same fixture. T5 lamps are smaller and more efficient than T8 bulbs.
While T5 lights are the winner between the two, they cost about 2x more than T8 options.
Differences Between T5 and T12 bulbs
T12s are an older generation of fluorescent lighting. They use electromagnetic induction, which is widely considered less efficient than the electronic circuits used in T8s and T5s. Visually, the T12 are 1.5″ in diameter, meaning they’re bigger than T5. In the growing space, smaller is often the better option. These relics of the fluorescent world likely don’t have much use in your indoor garden.
Are LED Lights Better Than T5?
If you read our article on Fluorescents vs. LEDs, you’ll see that we think that LEDs are, as a whole, better than fluorescents options. But if you look at T5s, specifically, it becomes much more interesting. A T5 produces an even light spread, low heat, and gives the grower a decent amount of control. So which option is best depends on the specific situation. Let’s dive into each category, so you can see for yourself if a T5 fluorescent or an LED makes sense for you.
LED lights produce very little radiant heat (about 11%), but fluorescent lights make a lot more (approximately 30 percent). In other words, LEDs do not emit as much heat as T5 fluorescent grow light bulbs in most circumstances.
That said, of the fluorescent options, T5s are incredibly cool, which is why they’re often used for starting seedlings. They are still a great option in terms of heat production.
Fluorescent lights, including T5s, are usually less expensive than LED lights. Since the early 1990s, however, LED technology has been reducing the gap. When it comes to fluorescent vs. LED lighting, fluorescents are currently the winner. On the other hand, LEDs provide more light at a lower cost over time, making them often cheaper in the long term.
For a long time, T5s were considered the most energy-efficient option for tube lights. But LEDs have closed the gap and are now estimated to save 45-65% in energy compared to their T5 counterparts. And as LEDs continue to improve, T5s are being left in the dust.
In comparison to LED bulbs, fluorescent lights and incandescent bulbs are inefficient. But of the fluorescent option, T5 is still the best option and very efficient.
LED Efficiency Fun Fact: According to Energy.gov, widespread LED use could save 348 TWh of electricity by 2027. That’s the annual electrical production of 44 1,000-megawatt electric power plants at today’s electricity prices, saving more than $30 billion.
One of the most impressive features of LEDs is their ability to customize your lighting to meet the needs of particular plants. These diodes can be set to emit light at a specific wavelength in the photosynthetic spectrum if desired (visible and non-visible). This means that the quantity of blue or red diodes in your lights can be changed.
The downside of LED customization is that it’s not always clear if your latest lighting change is working. You could get caught up in changing your LED spectrum constantly, trying to find that lighting sweet spot. It can end up being complicated and time-consuming.
With most T5 lighting, you’ll need to swap out red or blue bulbs, depending on the needs of your plants. You can also spring for a full-spectrum T5 light to get more of the colors at once. While there is technically less customization happening with a T5 fixture and lighting, it’s very plug-and-play. It’s a simple option for the grower who doesn’t want to spend loads of time optimizing a spectrum.
The Safest Choice
While intact, T5 tubes are entirely safe. But if you break a bulb, it could potentially be hazardous. Fluorescent tubes, including T5s bulbs, have a little bit of mercury gas in them. This gas is toxic to humans and can adversely affect our kidneys, lungs, and nervous system.
On the other hand, LEDs do not contain mercury, so they are a safer option. There is some (mostly unwarranted) concern that LEDs are harmful to the human eye, specifically the blue light produced. While staring directly at the light for long periods could cause damage to your retinas, it shouldn’t be a concern for most growers.
Best Spectrum For Plant Growth
Plants require full-spectrum light to thrive, and this is available with LEDs. This, however, is not always the case with a single fluorescent light, which is traditionally warmer or cooler. Plants really need both, especially in different stages of growth.
That’s not to say that T5s aren’t inherently ineffective in the spectrum space. Several growers prefer this option for smaller plants and seed starting.
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And indoor gardeners have long used a two-tube fluorescent fixture with one cold and one warm bulb or a full-spectrum fluorescent tube that emits warm and cool light to counteract this impact.
Which Option Lasts Longer?
The average LED bulb has a lifespan between 10k and 50k hours, making it a better option than either T5s, HIDs, or incandescent lights. A good fluorescent T5 grow light can be expected to last 20,000 hours.
Are T5 Tubes Being Phased Out?
Have no fear – T5 fluorescent tubes are still being produced. That said, because switching to LED lights can lower energy costs while maintaining relative efficiency, it’s not a stretch to think that T5s and other fluorescents could one day be removed from shelves. The UK government, for instance, is planning to remove fluorescent lights from stores in September 2023 to combat climate change.
Can You Replace A T5 With An LED Grow Light?
You can simply switch your T5 fluorescents with LED tubes that are designed to work in the same system. Doing this can cut your energy prices by as much as 50%.
Do You Need A Grow Room?
Grow tents are a good option for controlling variables, including light, water, temperature, and humidity. With the reflective material, grow tents can help you maximize the efficiency of your grow lights, as well. While not necessary for everyone, grow rooms or grow tents make an excellent option for indoor growers.
There are so many light bulbs and fixtures to choose from in the indoor grower space. Two of the best options are LED grow lights and T5 fluorescents. While LEDs are better in the long term, T5s are a more affordable option (upfront) that’s great for most growing needs. Get started with your indoor garden and purchase a grow light today.