T5 Lighting

T5 Lighting has become the standard for most reef aquariums. In the past, aquarists always struggled to get enough light into their aquariums. The invention of high output T5 lighting allowed hobbyists to keep corals and clams that could once only be kept under metal halide lighting.

Aquarium T5 High Output Fluorescent Lighting uses a special ballast to fire the bulbs. These ballasts are usually built into the light fixture, whereas metal halide lights oftentimes have large external ballasts that take up valuable space in the fish tank stand.

T5 Lighting Advantages

There are three advantages of T5 Lighting of Metal Halide. T5 lighting uses less power, so this cuts down on your electric bill. They produce less heat, which makes it less likely that you’ll need an aquarium chiller to maintain an appropriate water temperature. The average four to six bulb T5 fixture produces as much light as a 250 watt metal halide bulb, but the color can be easily controlled and the bulbs last one year before they need replacement. T5 Lighting Fixtures are also more streamline and weigh less, making them easy to hang.

T5 Bulbs

There are also a wide range of T5 bulbs available. Popular brands are ATI, Giesemann, UVL and Ice Cap. These manufactures make bulbs with varying colors ranging from 6,500K, which is a yellow to a 10,000K crisp white to a 420nm actinic. You can mix and match between brands and colors to create the ideal light color for your aquarium. Most fixtures come with bulbs and may offer two switches to control both daylight and actinic bulbs to create a dawn/dust effect. The stock fish tank light arrangement is usually a one to one ratio of daylight to blue bulbs. Some people are just fine with this combination, but you may prefer to replace one of the white bulbs with another actinic bulb. T5 Lighting Fixtures and replacement bulbs are readily available for saltwater aquariums 24 inches to 72 inches long. Standard bulb wattages are 24 watts, 39 watts, 54 watts and 80 watts.

T5 Lighting

T5 Lighting Fixtures

When selecting a T5 Lighting Fixture there are a few things you should consider. How many bulbs should I have? A general rule of thumb is one bulb for every six inches of aquarium width. For example, a 55 gallon aquarium is 12 inches wide and should have a four bulb T5 light. T5 lighting is more intense than power compact and VHO lighting. T5 Lighting will enable you to keep almost any variety of photosynthetic coral including acropora, montipora, zoanthids, mushrooms, leathers, frogspawn, brains and acanthastrea.

You should also consider the quality of the reflectors. Parabolic reflectors compared to the standard “three bend” reflectors can more than double the amount of light getting pushed back into your reef aquarium. If you are planning to buy a DIY or T5 Retrofit kit, then be sure to spend the extra money and get the best T5 reflectors. The parts required for a T5 retrofit kit are bulbs, ballasts, reflectors, end caps, stand offs, power cords and wiring. Finally, you should try to buy a T5 Lighting fixture with built in fans as this will increase bulb life and reduce heat.


Some of the newer T5 lighting fixtures will have standard daylight T5 bulbs as well as T5 bulbs with LED lights. These can be used for nighttime viewing or to add a shimmering effect to your saltwater aquarium during the day. Be very careful when handling these LED T5 bulbs as they are more expensive than the standard ones which cost around $25 each.

With T5 lighting you can have a beautiful saltwater aquarium, as seen in this picture below. It is the most versatile of the different saltwater aquarium lighting types because you are able to control the color of the aquarium simply by switching a bulb.


If you are planning out your saltwater aquarium, or just looking to upgrade, the best place to start your search for T5 Lighting is on the internet. You’ll find a much wider selection of bulbs and fixtures online and usually better pricing. If you are a bargain hunter there are always some great deals, just be careful if you buy a product from overseas. If you are looking for the best T5 light, start your search with ATI.