Fluorescent Aquarium Lighting

Fluorescent aquarium lighting is by far the most popular of the lighting types available. There is a wide range available and you will need to decide what will suite your needs.

Fluorescent lighting has remained very popular over the years as they are affordable to run with regards to your electricity bill. If you are a beginner with a small starter tank, the chances are you will have a standard fluorescent tube in it, which will be very cheap to run and replace.

Now with this lighting being around for many years, the technology has been improved and now there are a range of different types available:

1. N.O (Normal Output or Standard Fluorescent Light)

2. V.H.O (Very High Output)

3. C.F.L (Compact Fluorescent Light)

4. S.H.O (Super High Output)

Straight fluorescent tubes are normally given a T rating, which refers to the diameter (thickness) of the tube. As technology has improved, the diameter of these tubes has been getting smaller.

They start with T12 being the biggest size (38mm or 1½), then T8 is slightly smaller (25mm or 1). T5 aquarium lighting (15mm or 5/8) is still very popular even with newer technology bulbs available.

The smaller size means we can fit more bulbs into a smaller more compact fitting. This is a great help for people keeping planted aquariums that need lots of light.

The smallest fluorescent tube size so far is the T2 (7mm or ¼). This size is still being outsold by T5 aquarium lighting, but over time this may change.


As I mentioned before, the chances are that if your are starting out you will have one or more of these lights in your aquarium. These bulbs normally range between the 3000K and 10 000K mark.

For smaller fish tanks these lights are ideal and even with regular replacement will be quite cheap to operate. You will also find that there is a very wide range of bulb sizes and ratings for you to choose from if you are looking for new fluorescent aquarium lighting.

Replace these bulbs roughly every 8 months if you have a planted aquarium.


These lights are a little more expensive and from here onwards we are moving into specialized lighting for planted aquariums or larger and deeper tanks that need stronger light to reach the bottom of the tank.

These bulbs provide more light than the N.O bulbs and range from around 6000k to 20 000K. Besides the extra cost of the bulbs, these lights require special fittings that cost a bit more than normal fluorescent fittings.

The extra cost of these fittings is beginning to price these lights out of the market. The cost of replacing fittings that have broken can be quite expensive and you may want to look at some of the newer technology lights that we will be discussing later.

Should you have this type of fluorescent aquarium lighting in a planted aquarium, you should be looking to replace the bulbs every 12 to 14 months.


Compact Fluorescent Light These really great bulbs are also known as Power Compact lights, some people will also refer to them as Energy Saver bulbs when the refer to them for domestic lighting.

These bulbs can be bought between 3000K and 10 000K, but the main advantage is that they can fit into a standard screw or pin light fitting. This has been done by building the electronics needed to start the light into the bulb itself.

Now you know you will save money by using a cheaper standard fitting, which puts these bulbs ahead of the rest. Just take care and check that the fitting you use has a power rating higher than that of the bulb you use.

As with the V.H.O bulbs, these should be replaced every 12 14 months.


Super High Output are an advance in technology of the Compact Fluorescent Light. These have higher power outputs, require special light fittings and range from 6500K to 20000K.

The special light fittings will often consist of an aluminium dome to help reflect and direct light from the bulb. The style of these lights makes them perfect for deep fish tanks where the light needs to penetrate deep into the water and reach the base of the tank.

These fittings do make the initial setup quite expensive when it comes to fluorescent aquarium lighting, but if you own a large planted aquarium it is the way forward.

Bulb changes should be done around once a year or maybe longer if you have a good quality setup.

Return from Fluorescent Aquarium Lighting to Fish Tank Lights

Return from Fluorescent Aquarium Lighting to About Tropical Fish home