T8 Fluorescent Tubes - Frequently Asked Questions

Can I use T8 tubes in a T12 fixture?

Yes, the pins on both types are the same but the T8 tube will look slimmer if fitted into a T12 fixture. Most of the time the tube will work in this fixture, but sometimes the control gear in the fitting won't allow a T8 tube of slightly lower wattage to work.

What diameter are T8 tubes?

1 inch in diameter (eight eighths of an inch).

What length are T8 tubes?

This varies depending on the wattage. Our range of T8s vary in length, worth determining tube by wattage.

Are T8 tubes suitable for growing plants?

Normal fluorescent tubes will not work for growing plants, but special purpose T8 tubes are available for growing plants. These are called Grolux tubes which provide plants with the correct kind of light to encourage growth.

How efficient are T8 tubes?

T8 tubes typically produce the same light as the older, more inefficient T12 tubes but consume about 40 percent less power in the process. A typical 40w incandescent lamp used in the average living room will produce about 450 lumens whereas a similar wattage T8 (4ft 36w) will produce the same level of light and use a fraction of the wattage.

How many lumens in a T8 tube?

Lumens vary depending on the wattage. Typically the higher the wattage the higher the lumen output. For example the most popular T8 tube (2ft 18w) has a lumen output of 1350, where as a 5ft 58w has a lumen output of 5200. However the quality of the tube will affect this rating.

Do you sell T8 tubes in bulk?

Yes we do. Our prices are very competitive and we win the majority of all bulk enquiries. Most bulk prices can be seen on our website on the product pages.

What is the power consumption of T8 tubes?

The nominal power consumption of a T8 tube is the wattage stated on the tube itself. However other aspects affect the actual power consumption within a fitting. These depend on how many tubes are in the fitting and how many hours they will be in use for. Exactly how much it will cost to run depends on each individual application.

How is a T8 different to a T5?

A T8 is eight eights of an inch and a T5 is five eights of an inch. T5s are the latest energy saving fluorescent tubes in front of T8. T8s are higher efficiency and T5s are the highest efficiency. T8s are more commonly seen due to them being around for longer. T5s are generally thought to be a lot more expensive than their older brother, but this simply isn't the case anymore. T8s can be run on switch start and high frequency control gear, whereas T5s are high frequency only.

Do T8 tubes come in different colours?

Yes, the most common colour options are: 2700 kelvin (extra warm white) 3000 kelvin (warm white) 3500 kelvin (standard white) 4000 kelvin (cool white) 6000 kelvin (daylight).

There are other colours such as 8000 kelvin (sky white) which are more suited to specific applications such as printer inspection lamps. These are normally available through special request and aren't used in normal domestic applications.

My T8 tube is flickering, what can I do?

Check your tube is in the lamp holder properly to start with as well as any loose wiring that may be visible. If that fails to sort the problem, start by changing the starter if it's a switch start type. Followed by the tube. If neither of these resolves the issue, then the ballast is at fault and will need a replacement rewiring into the fitting. If it's a high frequency fitting there can only be two things at fault. These are the tube itself and the ballast, so it is best to change the tube to start with, followed by the ballast.

How long do T8 tubes last?

The average T8 tube will last for between 15,000 and 20,000 hours.

How do I install T8 tubes?

See our handy video and step-by-step guidance on how to install fluorescent tubes safely.

Can I replace T8 tubes with LED?

It is possible to replace your T8 fluorescent tubes with LED tubes. Our T8 LED tubes are a direct retrofit, meaning there is no need for lamp high-frequency control gear as the tubes are wired straight to the mains.

If you’re interested in finding out how much energy and money you could save by switching your T8 tubes to LED, take a look at the table below:

Length/type of tube


Electricity cost per year

2ft fluorescent tube



2ft LED tube



4ft fluorescent tube



4ft LED tube



5ft fluorescent tube



5ft LED tube



6ft fluorescent tube



6ft LED tube



8ft fluorescent tube



8ft LED tube



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Published 2015/10/15

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