REEF TANK LIGHTING by Charles Pagliaro

Title: Reef Tank Lighting

Author: Charles Pagliaro

Article:
Reef Tank lighting is one of the most important aspects of reef
keeping and undoubtedly the most discussed debated and disagreed
about too!

Proper lighting intensity is essential for the corals to carry
out the process of photosynthesis, the process through which
they create energy needed to survive and grow. Whatever the
approach or equipment be, the ultimate goal of al lighting
methods is to provide photoperiod, intensity and proper spectrum
for your reef inhabitants to flourish and thrive easily.

The commonly used phrase, "watts per gallon," is a way of
expressing the lighting necessary for a tank by the ratio of the
power used to illuminate the tank divided by the tank size in
gallons. Many hobbyists suggest that an adequate amount of light
would vary between four watts and six watts per gallon for low
light coral and as much as ten watts per gallon (or more) for
light loving coral. While such a rule of thumb may initially
sound like a good idea, it should only be used as a rough
guideline and not as a strict rule. Obviously, such a loose rule
is misleading, and aquarists need to consider more than just
"watts per gallon." Specifically, they must take into account
the height and overall size of the tank.

Lighting in the reef aquarist parlance is generally expresses in
"Watts per gallon". A thumb rule suggested by many says that
light should vary between four to six watts per gallon low light
coral and about 10 watts for corals with high light intensity
needs. But this is not a hardcore researched rule and should
only be used as a rough estimate. There are other factors like
the overall height and depth of the tank before making a choice.

A very innovative method of using a multi-light system with
timers or controllers to vary the number of lights on at any
given time is probably the most effective one. In this system
usually one bulb remains on for an hour, then all the bulbs for
10 hours and then just one is left on for next hour. This method
actually simulates the sun passing over. This is as close one
can get to re create the natural lighting mechanism of the sun.

There is no doubt that steady advances made in the light
manufacturing industry have made these equipments better and
better and more efficient.

The solution for your reef tank can vary in price from
inexpensive to very expensive. What suits you depends upon the
kind of life you want in your tank.

Two primary lighting equipments available in the market and
widely used are Fluorescents and Metal Halides (MH).

There are several variants of Fluorescents. These are the least
expensive or rather value for money choice and are suitable for
practically all light choices. These are relatively cool
(literally speaking, not metaphorically!). And generally they
last for many months before requiring replacement. Examples of
different fluorescents are: Normal Output (NO), High Output
(HO), very High Output (VHO), Power Compacts (PC) and T5's.

Among all the variants in fluorescents you can call Power
Compacts a next generation fluorescent bulb. They have a modern
twin tube design, basically a fluorescent tube that is bent in
half. Therefore much greater light intensity is produced than
other standard fluorescent variants. The fluorescent tubes are
available from 10 to 130 watts and can last up to a year to two.

You should opt for a fluorescent if your reef tank is not very
deep. There are some corals like SPS corals for which the light
intensity of fluorescent is not enough. So keep these points in
mind while thinking of a fluorescent.

The other popular option is the Metal Halides. There are
different parameters to be considered here too. They are the
most intense of all available lighting systems. If you have a
tank which is deeper than 20 inches, this is what you may
consider to buy, as halides have greater capacity to penetrate
to depths beyond 20 inches. Apart from the utility they beautify
your tank also by producing sparkling glitter lines.

About the author:
So if you want to have a successful reef, know your tank and
corals well and then make an informed choice. Only then 'Let
there be Light'! When Looking to buy live coral there is only
one source online: Buy
Live Coral