The 9 Best T5 Grow Lights
This wiki has been updated 19 times since it was first published in December of 2015. Now, we know you won't be using these for anything illegal, so we're happy to offer this selection of T5 fluorescent grow lights. Whether you're looking for the standard or high output variety, our favorites include options that are ideal for indoor cultivation of flowers, fruits, vegetables and all kinds of herbs -- ALL kinds. When users buy our independently chosen editorial recommendations, we may earn commissions to help fund the Wiki. Skip to the best t5 grow light on Amazon.
What Is A T5 Grow Light, Anyway?
The ultraviolet light makes the interior coating fluoresce, and turns it into the visible light that we see when we turn on fluorescent lamps.
Rated for a 10,000 hour lamp life, CFLs will last only half as long as tubes.
Navigating the differences between grow lights can be confusing for consumers, so we've written an explanation to help you understand where T5 grow lights fit within the larger spectrum of available fluorescent grow lights.
Fluorescent bulbs are good for propagation, vegetables, fruits, and tender plants. In comparison to incandescent bulbs, fluorescent bulbs use less electricity to generate more light. They're more efficient and get less hot, which is critical when it comes to plants. Different spectral options (color temperature) allow growers to choose between daylight lamps, which are better suited to propagation and vegetables, or bloom lamps, which are suitable for larger flowering plants (don't worry, we'll talk more about that later).
Fluorescent bulbs, which are usually rated as having a 20,000 hour lamp life, last about ten times as long as incandescent bulbs. As previously mentioned, you can choose from T5, T8, and T12 fluorescent bulbs, but T5 bulbs have the smallest diameter and best watt-to-lumen ratio. They're also the most efficient.
On a more technical level, fluorescent bulbs are glass tubes that have been injected with mercury and gas, and feature electrodes at each end. The inside of the tube is coated with a fluorescent material, phosphor powder, which is activated by ultraviolet light—think about the black lights that were pretty much the coolest thing growing up. When voltage is applied by turning the lights on, the electrodes heat up and emit electrons into the chamber. These electrons ionize the gas inside the chamber, in turn causing the mercury vapor to create ultraviolet light. The ultraviolet light makes the interior coating fluoresce, and turns it into the visible light that we see when we turn on fluorescent lamps.
88 There are also compact fluorescent bulbs, or CFLs, but they have a lower watt-to-lumen ratio. This means that CFLs require more energy to generate the same light output as the tubes. Rated for a 10,000 hour lamp life, CFLs will last only half as long as tubes. One benefit of CFLs is that they work with standard light sockets, and, being more compact, may work in smaller spaces that cannot accommodate fluorescent tubes.
How To Create Your Perfect DIY Indoor Garden
Buying your T5 fixtures is one thing, but setting up your indoor growing operation is another. Although there are some costs associated with creating and maintaining an indoor garden, the benefits are well worth it.
Whether you're growing fruits and vegetables or more, ahem, medicinal substances, an indoor growing operation lets you create organic substances from within the confines of your very own home. Gardening indoors also gives you the opportunity to start growing seedlings earlier in the season, and can improve your germination and plant survival rates by offering a more stable, insect-free environment. Here's a step-by-step guide to planning your indoor garden.
These greatly increase the efficiency of your bulbs, ensuring that little light goes to waste.
Before buying the T5 fixtures, you need to decide where and how you'll be setting them up. For most indoor gardens, this means purchasing shelving units, unless you're planning a small garden. (Check out this great indoor window garden inspiration. Are you feeling inspired yet?) You may already have shelves you plan on using, but if not, you'll need to buy shelves.
When deciding on shelving, take into account the dimensions of available fixtures—you'll want to make sure that your shelves are wide enough to accommodate the fixtures you buy. Also consider how many plants you plan on growing, how much space they'll take up as they grow, and where you'll put things like gardening tools. In terms of materials, most growers opt for metal shelves. Although it's highly unlikely that your setup would start a fire—unless you've done something horribly wrong—it's safer to stay away from wood when dealing with a complex electrical grow light setup. Metal shelves also offer easy ways of mounting fixtures, and unlike wood, aren't prone to rotting when wet.
Check out commercial or restaurant shelving units, which are metal, sturdy, and available in many sizes. Sometimes they come with casters, which is handy if you plan on reconfiguring your garden later on.
Buy the T5 fixtures. You should plan on hanging one fixture per shelf, and again, make sure that the dimensions of your T5 fixture are compatible with the size of your shelves.
Also consider what color temperature of light your plants need. Most T5 fixtures are available in either 3000K or 6500K, but there are some made in other temperatures, too. The higher the Kelvin rating, the bluer the light, so 6500K light is cooler than 3000K, which is warm light. Lamps at 6500K are most similar to daylight, and are usually called grow bulbs.
Choose 6500K T5s for vegetative growth, starting plants from seed, and for promoting general upwards growth. In contrast, 3000K lamps emit more yellow-red wavelength light called warm white, and are usually referred to as bloom bulbs. Choose 3000K T5s for flowering and bulking up plants. Alternately, some growers use a combination of 3000K and 6500K T5s. Read more about color temperature of grow lights here.
There are also T5-HO and T5-VHO fixtures, which stands for high output and very high output, respectively. While these T5 options do put out more light, they also use more electricity, and the watt-to-lumen ratio is slightly worse than that of regular T5 bulbs.
Purchase other supplies and hanging hardware if it is not included with your T5 fixtures, and set up your lights. What you'll need is dependent on your fixture, but in most cases, some chain, S-hooks, and zip ties will be sufficient. Using chain allows you to adjust the distance between your lamps and plants as your plants grow taller.
To determine if you need a power strip, plan out how you'll connect your fixtures to power. You may choose to plug your lamps into a single surge protector. Because T5 fixtures are quite efficient, they can usually be daisy-chained together, and manufacturers will specify how many of your fixtures can be safely connected. During this step, think about how to minimize the number of switches you'll need to turn on each day. This would also be an appropriate time to consider installing a programmable timer, which would automatically turn the lights on and off each day.
Plan to hang your T5 lights anywhere from 3-8 inches above your plants. In terms of light cycles, research what your plants need. Depending on what this plant would experience growing in nature, it could need a 12/12-hour cycle or a 22/2-hour cycle. In general, **more light increases growth**. When you're first getting started, you'll want to monitor your plants closely and adjust the hanging distance or light cycles as needed.
- Finally, consider installing reflectors. These greatly increase the efficiency of your bulbs, ensuring that little light goes to waste. Reflectors can be installed on the T5 fixtures or walls of your garden area, but your fixture might come with pre-installed reflectors. For wall reflectors, most growers use mylar sheeting. Avoid aluminum foil which can cause hot spots that burn your plants.
An Early History Of Horticultural Applications Of Electric Light
The history of grow lights—or more broadly, plant lighting—parallels the general development of electric light sources. In his paper, "A Historical Background of Plant Lighting: An Introduction to the Workshop," Raymond Wheeler identifies three early types of lamps that were used in horticultural contexts: carbon arcs, incandescent filament, and low-pressure gaseous discharge lamps.
The earliest type of lamp with applied uses in horticulture was the carbon arc lamp. According to the Edison Tech Center, in addition to being one of the first commercial applications of electricity, the carbon arc lamp was the first widely-used electric light. The carbon arc lamp used two carbon rods separated by a gap, which would form an electric arc when voltage was applied.
Horticultural applications of the carbon arc lamp date back as early as the 1860s, with an 1861 study performed by Mangon. More prominent studies came slightly later, with an 1880 study by Siemen, which included an economic analysis, and L.H. Bailey's 1891, 1892, and 1893 studies of carbon arc lamps in greenhouses.
The history of grow lights—or more broadly, plant lighting—parallels the general development of electric light sources.
In most of these early experiments, electric light was used as a supplementary form of light, essentially extending the natural sunlight plants received during the day by continuing with electric lighting at night. These lamps continued to be used until the 1940s, but became less popular due to the sparks and buckyballs they produced, making them prone to starting fires, as well as the harmful UV light they produced.
Beginning in the 1920s, incandescent filament lamps became the preferred form of electric light for horticultural research. Incandescent lamps feature a wire filament, enclosed in glass, that is heated by an electrical current until it produces visible light. In contrast to the carbon arc lamps, whose carbon rods had to be replaced frequently, the incandescent lamps could last for a few thousand hours. One such lamp was the Mazda lamp, first trademarked by General Electric in 1909. Many of the horticultural studies that used incandescent light found, however, that plants would grow unusually elongated stems. Many researchers ended up trying different combinations of incandescent and carbon arc lighting to achieve ideal growth results.
Finally, in the 1930s, researchers began using low-pressure gaseous discharge lamps to study plant growth in horticultural studies. Gas-discharge lamps feature chambers filled with a gaseous or vaporized substance—ranging from noble gas to mercury or sodium—which becomes ionized by discharged electrons when an electrical current passes through. When the electrons collide with the gas atoms, they become excited and emit light. In the case of fluorescent lamps, a type of gas discharge lamp, this light is ultraviolet and is illuminated by a fluorescent coating. When used in the context of plant growth, gas discharge lamps offered higher efficiency and more tailored light spectrums. The use of low-pressure gaseous discharge lamps eventually led to the realization that sodium lights offered great possibilities for plant lighting. This also marks the origin of the application of fluorescent lamps in horticultural contexts.
Since these days of early experimentation with electric plant lighting, scientists have developed a variety of lighting options that make just about any indoor garden a possibility. Thanks to progress, we can have gardens in our bathtubs, closets, attics, kitchens, and anywhere in between.
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