T5 vs T8 Grow Lights: What Are The Differences

It's a lot to keep in mind when you're growing indoors. Humidity, temperature, soil, and so forth are all factors to consider, and hydroponics adds an additional layer of complexity. Indoor growers are usually curious about the differences between T5 and T8 lighting as one of the most important factors to consider. To help you make an informed decision, we're going to compare and contrast these two possibilities in this post.

The difference between a flourishing garden and a dismal one can be made by using the correct interior lighting source. In all stages of plant growth and development, a grow light is a multi-purpose light bulb that mimics the energy and influence of UV rays or sunlight exposure. This light can be used to grow plants indoors or in areas where the weather is less than optimal.

Despite the fact that most artificial light sources are not unreasonably expensive, picking the wrong one for indoor cultivation might waste time and effort. As a result, it's vital that you evaluate T5 and T8 grow lights before making a final decision.

As far as differences go, what are the most notable ones? For your garden, which one is the best bet? We'll take a closer look at some of the most important distinctions and similarities between these options so that you can make an informed decision.

What’s the T?

A fluorescent light's wattage, shape, and diameter are used to classify it as fluorescent linear tube lighting. "T" stands for tubular, and "5" denotes that the bulb is 5/8-inch in diameter, which is why it's called T5. One-inch-diameter T8 tubes are very popular. Only the bulb's form and output can be determined by its T code. It specifies the lamp tube diameter and the level of energy efficiency.

The Difference

The names of these two fluorescent bulbs reveal their primary difference. The T8 bulbs have a diameter of eight-eighths of an inch (equivalent to 1 inch thick). 5/8 of an inch thick, the T5 bulbs are the thinnest. For many indoor gardeners, T8 grow lamps are preferable than T12 fluorescent bulbs since they provide more overall lumens and are more efficient.

The T5 high-output bulbs have an advantage over the T8 bulbs in that they are 9 percent more efficient, provide more light in a smaller area, and consume less wattage (75 to 90 lumens per watt). Moreover, the higher color rendering index (CRI) of T5 HO means that it is more aesthetically pleasing to look at. If you care about how the light looks to the human eye, but not to plants, then the color rendering index (CRI) isn't that essential.

T5 bulbs, on the other hand, necessitate more expensive and specialized fixtures. They also have a shorter lifespan of 10,000 hours, compared to the typical 20,000 and 30000 of T12s, respectively. It is possible to get longer-lasting T5 bulbs, so be careful to check this specification before you buy.

T5 Grow Light

The "T" in "T5" refers to the lamp-tubular shape of the fluorescent light bulb, however the "T" in "T8" refers to the size of the fluorescent light bulb. The diameter of the lightbulb is indicated by the number following the "T," which is the number of eighths of an inch.

Most T5 Grow Lights may be purchased for between $10.00 and $200.00 at most hardware and specialized stores, as well as nurseries. The higher-end models appear to have more positive consumer evaluations in terms of life expectancy and wattage, while the lower-priced models are more wallet-friendly for newbies in the field of gardening.


Using the T5 light as the primary or additional source of illumination in 35°C rooms creates a warm atmosphere. Light-emitting diodes (LEDs) are becoming increasingly popular because of their capacity to shine brighter light in a smaller area than other light sources.

Any type of Grow Light but especially when using a T5 light, little plants or fragile species may benefit from a modest fan to circulate the air in the area.

Two Styles Available

In terms of price, the T5 Grow Light may be purchased in both LED and Fluorescent versions. When it comes to choosing a product, having alternatives and choices is always a good thing because it allows for more conversation and study. Both bulbs have similar benefits and drawbacks, such as low energy levels and longer lifespans, so you can choose the one that best suits your gardening needs.

Higher Efficiency Rate than its Counterparts

Cost-cutting tactics have become a requirement and a reality in today's society due to the rising costs of almost everything. To make up for the costs they can't cut, people are finding creative ways to save money.

Numerous testing and consumer reviews have shown that the T5 Grow Light is more efficient than a comparable T8 Grow Light. There is a 9% difference in efficiency rates, which may not seem like much, but when you include in the difference in your annual electricity bill, it adds up. When you consider the absence of money spent on fresh food, there is a significant difference.

Can be more expensive than a T8 grow light

Gardening may be a costly pastime if you don't have the necessary tools, soil, mulch, and nutrients and fertilizers for your family. Because the price of seeds and seedlings can vary so widely, achieving good results in the growing process is essential. The T5 Grow Light might cost up to two times as much as the T8 Grow Light, despite the fact that Grow Lights can boost the chances of a successful, fruit-bearing plant.

T8 Grow Light

T8 Grow Light

Compared to the T5 grow light, the T8 model is approximately 40% smaller and has a diameter of exactly one inch (1"). These bulbs can't be used in growing systems because of their unique shape, which is longer than that of the T5 grow light.

With a range of manufacturers and pricing, you can find the T8 grow lamp at most hardware stores as well as specialist shops and nurseries. The LightingWill LED Grow Light received a lot of positive feedback on Amazon. There are four lightbulbs in a package, so you can grow numerous things at once even if it's more expensive.

Interchangeable With A Variety Of Lighting Fixtures

Because it may be utilized in more general fixtures without sacrificing power or wattage, the T8 light has an advantage over its predecessor. When using T5 Grow Light light bulbs, they must be put in a certain fixture before growth can begin, and some brands are only compatible with fixtures made by the same company. There is less short-term maintenance and/or costly repair when fixtures can be used with multiple types of light bulbs.

Life Span

In comparison to a T5 Grow Light, studies and experiments have shown that the T8 Grow Light has a longer lifespan. The T5 produces 20,000 more hours of UV radiation per year than the T8. However, it's always a good idea to check the bulb's wattage and power, especially when growing plants that demand specific amounts of light.

When Should I Use T5 Grow Lights?

T5's are around 12% more efficient during the vegetative and blooming periods.

In general, the best T5 grow lights are great for plants that are about to flower because they demand more intense light and have a higher watt density per cubic centimeter. In addition, T8 bulbs are less severe, so you'll have to set them closer to your plants to get the same benefits as T5 lights. T5s are easier to maintain in this situation.

When Should I Use T8 Grow Lights?

In terms of cloning and seeding, T8s may be your best option. Cuttings and seedlings are additional common uses for the T8. T8 bulbs are most commonly used in aquariums, although they are also used in horticulture. It doesn't matter if growers use these lights commercially or domestically; they can both stimulate plants and provide good supplemental lighting in greenhouses.


Indoor growers have a plethora of options when it comes to lighting. T5 and T8 fluorescents are two of the most common types.

The diameter of the fluorescent tubes is the fundamental difference between T5 and T8 Grow Lights. There are two sizes of T5s and two sizes of T8s: 5/8" and 1". In addition, T5 fluorescent tubes are slightly shorter than T8 fluorescent tubes, which is why they are more commonly used. This is an important point to keep in mind because it means that swapping out T5s and T8s on the same fixture may be problematic. Compared to T8 bulbs, T5 bulbs are both smaller and more energy efficient.

Although T5 lights are the better choice, they are nearly twice as expensive as T8 alternatives. T5s are more cost-effective in the long run than T8s, and they're ideal for most growing demands.

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