What are the benefits of T5 lighting?

As everybody knows, for good coral growth or even the survival of corals , especially hard corals, one of the critical parameters is light. With the advent of T5’s, (which incidentally only describes the small diameter of the tube and does not indicate the lumen output), and the development of the correct phosphor blends it has been possible to produce a fluorescent tube, which can emit 10% more light than the equivalent wattage from a metal halide bulb. This is achieved with a 40 % reduction in running cost and without the radiant heat problems that are associated with metal halide lighting.

The actual tubes themselves are significantly less expensive than metal halide bulbs and have longevity far in excess, up to 15000 hours. The T5 tube is only half the story. The narrow diameter of the standard linear T5 tube has allowed production by D&D of a highly efficient reflector. The reflector is gull wing in shape, which allows the light from the back of the tube to be utilised and not reflected back through the tube where it would be lost. This is only possible due to the narrow diameter of the linear format T5 as the light is reflected in a clear path away from the tube.

Aquablue Plus
A special 60:40 combination of 6000K and 22000K (approx) phosphor blend. It is specifically designed for reef aquariums mimicking sea water to a depth of one to twenty meters. It can be used for growing SPS corals up to 80cm in the aquarium. The tubes can be combined with Aqua Flora for freshwater, tropical fish and planted aquaria.

Actinic Plus
This tube has replaced the Deep Ocean Tube.

Its spectrum is generally as the deep ocean but as the name suggests it also emits high levels of Actinic Light. This is designed to make even the drabbest corals stand out by producing strong fluorescence.

Actinic Pure
Actinic pure is the latest of the latest T5 tubes produced by D-D.

It is not as blue as the Actinic Plus and has a pure actinic spectrum for the ultimate in fluorescence from your corals.

Mid Day 6000
Rated at 6,000 Kelvin with a spectrum designed to recreate sunlight in both fresh and salt water aquariums. This tube can be used on both freshwater and saltwater aquariums.
 

These tubes can be used in combinations.  For saltwater you can use the Aquablue in conjunction with the Actinic Plus to achieve a deeper blue hue.


ALGAE GROWTH

Please note: With high illumination of planted tanks growth is enhanced. However if there is an excess of phosphate the growth rate of unwanted and nuisance algae is likely to accelerate. To solve this problem we recommend that you use Rowaphos which successfully absorbs phosphate and silicate, removing the nutrients which the algae need to feed on without releasing back any of the absorbed materials.
 

Even in a change from metal halide lighting, many people find that the increase in light due to better distribution when using T5’s can have a positive effect on the growth of algae which can be a negative effect for the average aquarium owner. This is quite normal and only indicates that the aquarium water is too rich in nitrates or phosphates or both, which act to fuel the algae growth. Remember that in a reef tank, which is a closed system, the way that the light increases coral growth is by feeding the symbiotic algae (zooxanthallae) that grow within the coral. By removing either phosphate or nitrate from the tank it will remove one of the vital elements required for nuisance algae growth. Phosphates however are also an inhibitor to coral growth and act by restricting the process of calcification within the coral skeleton. In a reef tank this is a far worse effect than the increased algae growth on the glass. In both saltwater and freshwater aquariums the phosphate levels can be controlled to help starve out the algae by the addition of Rowaphos phosphate absorber, which is a man made chemical designed specifically to remove phosphate from water. The ideal level for phosphates within the aquarium is less than 0.015mg/lt measured as phosphorus, (0.046 mg/lt measured as PO4)

Compact T5 Units

With compact T5’s it is not possible to achieve the same amount of luminosity per watt due to its u-bend shape. Giesemann T5 tubes are have been designed straight to achieve maximum light output when used in conjunction with Giesemann reflectors.