While it’s true LED reef lighting offers a lot of programming and automation options, not everyone has made the switch or is unhappy with their existing conventional lighting system. In fact, some reef aquarists have actually switched back to MH and T5 fixtures.
We’ll take a look at this well-tested lighting technology and see why it is still used by aquarists, public aquariums, and coral propagation operations on a world-wide scale.
Could it be right for you?
The history of fluorescent and metal halide aquarium lighting
The fluorescent lamp remains one of the greatest lighting inventions of all time. Early prototypes were around in the 1800’s but the first commercial bulbs hit the market in 1938. The bulbs are constructed with electrodes on each end of the glass tube. The tube is filled with a minute amount of mercury that emits UV light when electric current passes from one electrode to the other.
The ballast controls the amount of current that is sent to the bulb. The glass tube has a phosphor coating inside. The coating changes the UV into useful colors that can be used to light a room or an aquarium. The phosphor coating determines the color temperature of the light.
In 1995, the T5 bulb was introduced. Smaller in diameter than traditional bulbs, the T5 became the standard for high-output aquarium light fixtures. Custom bulbs are available that provide light energy in variety wavelengths and colors with the goal of duplicating natural sunlight or adding specific wavelengths that are beneficial to coral growth and coloration.
Metal halide (MH) or high intensity discharge (HID) lighting makes use of a large glass bulb that contains a small quartz tube containing argon gas and a minute amount of mercury. The quartz tube also contains halide salts, like silver chloride, that are used to fine-tune the color produced by the bulb. When current is applied to the MH bulb, the tube glows like the sun.
Metal halide aquarium fixtures were designed to illuminate very deep aquariums but later the technology was scaled down for home aquarium use. Metal Halide fixtures require a larger ballast to fire-up and run the lamps.
Proven performance and economical price
Fluorescent T5 and metal halide lighting are mature technologies, meaning the bugs have been worked out and performance maximized. All of the early coral growing trial and error was made with these lights and are still being used today.
These lighting options continue to be very popular with reef aquarists for several reasons:
- T5 light fixtures cover the entire top of the aquarium for even lighting
- Metal halide is proven to grow all types corals
- Metal halide creates the most natural light shimmer effect
- T5/metal halide combo fixtures provide natural daylight and enhanced blue light
- Retrofit kits allow you to combine LED with T5 lighting
- Costs less than many high-end LED reef lights
- Easy to experiment with different T5 bulbs
- Many aquarists don’t need the full aquarium automation features of LED lights
T5 and metal halide lighting can be controlled with traditional aquarium timers. Some fixtures have multiple power cords, allowing you to gradually switch on and off individual lights to simulate dawn and dusk cycles.
The really cool thing is the availability of a wide range of bulbs and fixtures, making it easy to build a custom lighting system for your reef tank. Some aquarists have combined LED lights with these fixtures. There is no limit to the combinations to experiment with.
I’ve highlighted a few of the many lighting options from Hamilton, a leading supplier of T5 and metal halide aquarium lighting.
This slim metal halide fixture is compact but packs a lot of light. At only 2.5″ tall, the 150-watt bulb provides full spectrum light suitable for corals and other reef-builders. You can hang the light above your tank or use the arm kit. The built-in reflector and 20,000K bulb provides full spectrum and blue wavelengths that reef tanks need. The 12″ x 10.5″ fixture is perfect for smaller tanks or can be used in multiples with larger reefs.
If you’ve got a wider or deeper aquarium, you’ll love the penetration power of the Cebu Sun system. Combining high output T5s and a 14,000K bulb provides plenty of light, even for SPS corals. The Cebu Sun systems are built to order in the US. They’re available in a variety of configurations with lengths from 24 to 72 inches. MH bulb choices range from 150 to 400 watts depending on fixture length. The multi-faceted reflector drives the light through the water, bathing your corals in life-giving light. You’ll love the beautiful light shimmer too!
Maybe you’re using a fixture that runs compact fluorescent bulbs. Hamilton makes top-quality replacement bulbs that will breathe new life into your CF light system. The 50/50 bulb combines a Real Blue Actinic tube and a 10,000K tube in one CF bulb. These are really great for shallow tanks that don’t need intense light, like FOLR tanks.
Want to retrofit on existing fixture or build your own reef light? The Aruba Sun combines high output T5s with blue moonlight LEDs. The 10,000K T5s are supercharged by German mirror-polished reflectors that direct the light down into the reef. Moisture-proof end caps keep the bulbs dry and secure. The kit also includes blue LEDS for moonlight. The LEDs have a separate power cord, making it easy to simulate dawn and dusk with a timer. The retrofit kit is available in 2x 24-watt up to 2 x 80-watt configurations.
No matter if you’re building a custom DIY light rig, adding to an LED system or just setting up your first reef, we’ve got everything you need to properly light your tank. Be sure to check out all your options in our lighting section. If you need help, our knowledgeable support staff can guide you in the right selection.