Proper lighting in reef aquariums is probably the most debated topics in the hobby. There are many opinions and really no one correct way or perfect lighting system for your aquarium. However, there are many options and all these options can make the beginner or even advanced reefkeepers very confused. Proper lighting is essential to the long term health and vitality of your reef aquarium. Hopefully the following will help you to decide on the best lighting for your reef aquarium.

What is in your tank? : Reef tanks need more lighting than fish only tanks (planted freshwater tanks also require ample lighting). If you have a single coral you need to treat the entire tank as a reef tank (in terms of lighting and filtration). A tank with live rock--where you are cultivating the photosynthetic animals or macro algae commonly found on live rock--needs to be treated as a reef tank. Fish tanks with live rock used for the purpose of beneficial bacteria or natural appearance do not need high output lighting. Hard corals need more light than soft corals. For example, small polyped stony corals, such as Acropora, definitely need high-intensity metal halide lighting. If you have a reef tank you should think about some form of high intensity aquarium lighting such as VHO Lighting , Compact fluorescent lighting or Metal Halide lighting.

What is the size and depth of your tank? . Experts often give recommendations for determining reef aquarium lighting wattage needed based on the # of gallons in a tank. The ratios given range from 1.5 to 6 watts per gallon. However, since a light's intensity is dramatically decreased with distance, a tank that is deeper needs more light than a relatively shallow tank holding the same number of gallons of water. According to the Inverse Square Law: The intensity of light falling upon an object decreases in proportion to the square of the distance between the object and the light source. So, a doubling of distance between the lamps and the organisms will result in a need for four times as many lamps for the organisms to grow at the same rate. If your tank is over 20 inches deep you should definitely consider metal halide lighting  because metal halide lamps are the most concentrated form of aquarium lighting. To help you determine the proper lighting configuration for tanks of various sizes.

Other important reef tank lighting considerations:
Retrofits or Kits
If your aquarium has a canopy (a box cover) you probably want an aquarium lighting retrofit. The retrofit will need to be screwed into the canopy. There are compact fluorescent retrofits also email us at service@reeflections.com   about retro-fit's.

If you don't have a canopy you will probably want a Hood. Hoods lay on the glass/acrylic top and or edges of the tank. They are extremely easy to set up and come available as either Compact Fluorescents, or Metal Halides or a combination.

Spectrum
The natural habitats of many common reef aquarium organisms have a bluer light spectrum." ( Deeper water is bluer because as one travels deeper into water the longer light waves, toward the red end of the spectrum, are filtered out. ) Included in this category are stony and soft corals, live rock and anemones.

Reef tank aquariums are commonly lit with a combination of daylight and blue (aka actinic) lights to emulate the natural environment. Almost all lighting systems we sell, with the exception of those specifically label as for freshwater planted tanks, will have the proper balance of daylight and actinic lamps.

Two of the Basic Types of Lighting

There are two main basic types of lighting used for reef aquariums, fluorescent lights and metal halide lights. Reef keepers typically use only fluorescent lights or a combination of metal halide and fluorescent lights to illuminate their tanks. Each has its advantages and disadvantages.

Fluorescent lamps are long and produce a more spread out even-looking lighting. Metal halide lamps will produce a more point source spot type lighting.

Reflectors used for your lights are critically important in getting the optimum utilization of the light produced from any type of lamp. Parabolic shaped shiny metallic reflectors are generally better at getting more light into your aquarium than any other type of reflector materials.

Also, the lamps and reflectors must be cleaned frequently with a damp cloth to remove salt spray and dust to get the most out of each lamp. Generally, fixtures should be about 8-10 inches above the water surface to get maximum utilization and lamps should be protected from water splashes that will cause hot lamps like metal halides to crack or sometimes explode. A cracked lamp will emit excessive UV radiation and can easily bleach and kill many corals quickly, so it is advisable to clean and check all lamps at least monthly. Fluorescent lamps should be replaced every 6 months and metal halide lamps generally should be changed about every 12 months. The lamps will produce light for a much longer period but the spectrum and intensity shift and decrease slowly over time. Corals will become slowly adjusted to these lamp changes over time and if you then change a lamp suddenly the corals will be subjected to much more intense light and will be adversely affected. Keeping with a strict schedule of lamp changes will prevent this problem.

Spectrum---The Color of Light

Corals look best and grow best under light with a more blue coloration,  we advise having more blue spectrum lamps on your reef aquarium.

Light color that a lamp produces is measured in degrees Kelvin, abbreviated K. Kelvin ratings do not relate to light intensity directly, a higher K number does not represent more intensity, in other words a 20,000K lamp is not more intense than a 10,000K lamp. This is something that a lot of people get confused about.

Lamps for aquariums will have K ratings listed on them and this relates to the color temperature, the lower the K number the more yellow-red the light will be from that lamp and the higher the number the more blue the color of the light from that lamp. For example, a 6500K lamp will be very yellow in comparison to a 20,000K lamp that is very blue. Actually, intensity tends to decrease as the K rating increases. So, a 6500K lamp will produce more light than a 10,000K lamp and it will produce more light than a 20,000K lamp at the same wattage.

Wattage and how Much Light Do You Need?

Optimum intensity is also debated in the reefkeeping hobby and there are no firmly set guidelines. If you ask many successful hobbyists you will get many different answers about how much light is needed to grow corals. A lot depends upon what type of corals you wish to keep. While the corals we keep in our aquariums all originate from tropical waters and are use to intense sunlight, some are more adaptable than others to captive life and changes in light intensity so that's very important to keep in mind.

Acropora corals and other smaller polyp stony (SPS) corals are less adaptable to varying lighting conditions than larger polyp stony (LPS) corals and soft corals. Often people will keep soft corals and some LPS corals very healthy and growing well under just regular fluorescent lamps or power compact fluorescent lamps and SPS corals under a combination of metal halide and fluorescent lamps.

The wattage of the lamps and type of ballast used to run the lamps will determine the intensity of the light the lamps produce. Over the years hobbyists have discussed crude measurements of the amount of light corals need to thrive. Most successful reef aquarists will use about 6-8 watts of light per gallon of tank water for Stony, SPS and clams, even more light in real deeper tanks, and less light 3-6 watts for soft corals. With higher light levels on your tank you will generally have the ability to successfully keep a wider variety of corals than with lower wattage. If you have only regular output fluorescent lamps you will only be able to keep a few corals alive, but if you have metal halide lamps in combination with fluorescent lamps you will be able to keep almost all corals healthy and thriving.

Types of Fluorescent Lights

Normal Output Fluorescent (N.O.)
These lamps are the same as you find in home and business ceiling lighting fixtures. For aquariums they are usually sold with fish-only tank set ups often coming as a package with a tank, glass top, and strip light. In a smaller aquarium of maybe 30 gallons or less they can be used to keep some corals successfully. Low light demanding corals such as mushrooms and some Zoanthids may do fairly well with this type of lighting. Other lower light demanding corals may be OK if you have several lamps over the tank. This type of lighting would be considered the lowest intensity usable for a reef aquarium. If you are on a tight budget you can keep some corals and also fish and invertebrates in a reef aquarium illuminated with N.O. fluorescents. This lighting would not be appropriate for any corals that have higher light demand.

Power Compacts (PC)
This type of fluorescent lighting is commonly available at a relatively inexpensive cost. Many hobbyists choose this type of lighting and it is the most commonly used for reef aquariums. I would also consider this type of lighting of lower intensity. You can successful keep a reef aquarium with these lamps, but as with the N.O. fluorescents I would suggest only soft corals and some LPS corals. If you have several lamps over a smaller tank then this type of lighting would be OK for many varieties of soft and LPS corals, it would not be appropriate for most SPS corals.

High Output (H.O.)
High output lamps will allow you to keep most corals thriving if you use enough of them over your aquarium. They are now commonly called T-5 lamps. Again, using a combination of lamps to get a more blue color will make your corals look their best. Some hobbyists are quite successful keeping even the more difficult to keep SPS corals including many Acropora with T-5 lamps. These lamps are thin and many can be included in a homemade type canopy and they are now readily available in retro fit kits. They also have an advantage over many other types of more intense lighting used for SPS corals in that they will not heat the water as much as high wattage metal halides. As with other fluorescent lamps these should also be changed about every 6 months. More hobbyists are using T-5 lighting successfully now and it is a serious choice for beginners and advanced hobbyist. Many folks will also use T-5 fluorescent lights in combination with metal halides.

Very High Output (VHO)
VHO lamps have been used for many years by many hobbyists to keep all types of corals successfully. They are typically operated with electronic ballasts and do not tend to overheat your aquarium as high output metal halide lamps. No other lamp can produce amazing glowing colors in corals like the VHO actinic lamp.

About Aquarium Compact Fluorescent Lighting
Compact fluorescent ( aka power compact ) aquarium lighting utilizes fluorescent bulbs that are bent in half. These VHO lamps deliver a higher concentration of light energy in a smaller space than straight tubes do, although the light concentration is less than with metal halides . They are also different from regular fluorescent tubes in that they are single ended, as opposed to the typical double-ended construction of most other fluorescent lighting.

There are two different incompatible standards for compact fluorescent lights, the straight pin style (aka European), and the square pin style (aka Japanese or Panasonic). The straight pin connector has the four pins in a straight row while the square pin connector has the pins in a square configuration. Current USA Bulbs are all square pin. Most of the Coralife lights we sell are straight pin, but some are square pin. Neither standard is superior--you just have to be careful when buying replacement bulbs that you get bulbs with the correct pin configuration.

Hoods & Retrofits
If your aquarium has a canopy (usually a wood box cover) you probably want a retrofit, such as the Aqualight Retrofits  or Current USA retrofits . Both the Aqualight and SunPaq come complete with the bulbs mounted to a reflector--you just need to screw the reflector to the canopy. The only other thing you might need to complete your lighting system is a canopy fan  to dissipate the heat. You might also want to consider getting a VHO Retrofit s . VHOs (Very High Output) lights are fluorescent lights also, and in many cases you can get the right amount of light more easily using a VHO Retrofit. For tanks deeper than 24 inches and tanks with hard corals you might want to consider a metal halide retrofit. Please mail us at service@oceanreeflections for any questions.

Color Temperature
You will see bulbs listed as Actinic, 420nm Actinic, 10,000K, 6,700K, SmartPaq , 50/50 and in a variety of other ways.   But generally speaking you just need to know the following. Reef tanks generally do better with half the lighting to be actinic lighting and half the lighting to be full spectrum daylight lighting. For the actinics any bulb listed as an actinic-- whether it is a True Actinic, 7,100K Actinic, Actinic or 420nm Actinic --will be adequate. For the daylight bulb the best bulb for corals is the 10K (aka 10,000K) bulb. 6,700K and 8,800K bulbs are also fine. In many situations, because you will only have one row of bulbs, you will to get a 50/50 bulb in order to be able to spread the actinic and full spectrum daylight lighting evenly. The 50/50 bulb has one half of a single power compact bulb actinic and the other side full spectrum daylight. The Current USA 50/50 bulb is called the SmartPaq and the Custom SeaLife 50/50 bulb is called the SmartLamp.

How much Light Do I Need?
This is a very complicated issue, but here is the general rule of thumb. For a tank with only soft corals or live rock, you'll want a lighting system with about three watts of light per gallon. For hard corals and clams you'll need about five watts per gallon. For tanks over 24 inches or with SPS or Clams you may want to consider a metal halide . Always keep in mind that the farther the light is from the coral, the less light will reach the coral. So you may want to put corals or clams needing more light toward the top of your tank also.

Metal Halide Lamps

There are two types of metal halide (MH) lamps, single ended screw-in, also called Mogul base, and double-ended lamps called HQI. Metal halide lamps have a smaller tube section enclosed by a larger glass envelope, the HQI lamps are basically just the inner section without the larger outer envelope. HQI lamps require a different type of fixture than the screw in lamps. The outer glass envelope on a screw-in lamp provides some UV protection and since the HQI lamp does not have this outer glass envelope it must be housed in a fixture with UV absorbing glass. Because HQI lamps are smaller, the fixtures used for them are smaller and sleeker and now many types of unique HQI fixtures are available at www.oceanreeflections.com  Screw-in type lamps can be housed in full metal hoods or pendants and also are available in retro fit kits for installation into your own canopy.

MH lamps produce intense point source light that is especially good for SPS type corals and clams as well as other corals. They do produce lots of heat and temperature control will be an issue when using these lamps.

HQI MH lamps are available in 150 and 250 watts and screw-in MH lamps are available in 175, 250, 400, and 1000 watts. For Acropora and brighter colored SPS corals 250, 400, and 1000 watt lamps are the most commonly used, 250 watt HQI lamps also work well. Kelvin ratings typically used for reef aquariums range from the very yellow 6500K up to 20,000K blue lamps. Also available are 10,000K and so-called 14,000K and 15,000K lamps, although these designations are often mostly manufacturer marketing than real distinct values. Each manufacturer's lamp will vary in color, one 10,000K lamp may be more yellow than one from another manufacturer yet both will be labeled as 10,000K. So, the Kelvin ratings on MH lamps are not precise and do vary.

Many use and recommend 20,000K lamps along with VHO actinic fluorescent. Typically, the actinic lamps will be on for one to two hours before and after the MH lamps simulating dawn and dusk. Most hobbyists will use the MH lamps for about 6-10 hours a day simulating the height of intensity of tropical sunlight.

DO YOU NEED METAL HALIDE AQUARIUM LIGHTING?
There is no other practical lighting source for an aquarium that will provide as much light intensity in a small space as metal halide aquarium lighting. This is why they've become popular for reef aquarists. The need for light intensity provided by metal halides becomes important as tanks become deeper. Generally, metal halides are practical for reef tanks 16 or more inches deep  or a must with become a necessity for tanks deeper than 36 inches. Even deeper tanks and more demanding stony corals, such as Pavona, Goniopora, and certain Acropora species need 250- or even 400-watt metal halides for success. SPS, and clams would require Metal Halide even for shallower tanks.

THE GLITTER EFFECT
Many people find metal halide aquarium lighting more attractive than fluorescent lighting types such as VHO or power compacts because of the "glitter effects" As in a natural reef environments surface waves act as a lens that focuses light and creates "glitter lines." These glitter lines, familiar to divers, appear as flashes of light of high intensity and short duration and are very attractive to the eye. In reef aquariums these glitter lines or flashes can be created through the use of point source lights, such as metal halide lights, and surface agitation of the water with pumps. Fluorescent lighting is more diffuse and less intense and does not create these effects though the Solaris Led System does to some degree. Whether this flashing light has any advantages to the corals is not well known. 


POINTERS

• Small polyped stony corals, such as Acropora, definitely do better if metal halide lighting is used.
• Low light requiring animals, such as mushroom corals or non-photosynthetic gorgonians, or corals of the genus Tubastrea, will do well under regular output fluorescent bulbs.

A couple pointers regarding light penetration:

METAL HALIDES AQUARIUM LIGHTING FOR SMALLER TANKS
Almost all metal halides are at least 70 Watts, and all the metal halides sold by www.oceanreeflections.com are 70 Watts and over, so they may be too much for smaller aquariums. However, if you use a Pendant, the fixture can be placed some distance from the water, thus reducing the intensity, and spreading the light out better over the entire aquarium.

OVERHEATING
Overheating is a potential threat when metal halides are used. However, with good air circulation (fans) or an  cool air-conditioned house will help keep you from increased water temperatures occuring. Chillers can be used to offset any temperature gains. Whenever installing metal halides, be sure to make frequent water temperature checks.  Any question regarding chillers or fans we can be reached at service@oceanreeflections.com

SPECTRAL CHARACTERISTICS
For photosynthesis to occur, aquarium lighting should duplicate the spectrum of sunlight. The 5500K, 6500K and 10000K Metal Halide bulbs are full spectrum bulbs with all the colors of sunlight. Yet, the natural habitats of many popular reef aquarium organisms have a bluer light spectrum--a light spectrum around 7100K that is commonly referred to as actinic. ( Deeper water is bluer because as one travels deeper into water the longer light waves, toward the red end of the spectrum, are filtered out. ). For effective lighting you need both the full spectrum daylight provided by the metal halide bulbs along with the actinic lighting provided by the power compact bulbs.

ENDING

As you can see are many types of lamps you can use for your reef aquarium. Because the lighting is so very important to the health of the animals in your care and because of the expense of most lighting equipment, it is VERY IMPORTANT to seek as much information and advice as possible and educate yourself  before deciding upon the best lighting for your tank we at www.oceanreeflections will be more then happy to assist with any questions  we can be reached for all questions at service@oceanreeflections.com   Thank you! 

You have come to the write place customers if you are looking for one of the biggest selections and lower prices on Marine and ReeF lighting on the internet we carry a huge selection of all kinds of lighting, www.oceanreeflections.com carries everything from reef metal halide lighting systems to fluorescent lighting systems and T5 lighting systems to combo light systems, we also carry most replacement bulbs for most of the lights we carry, we also carry moon lights and  retrofit kits and a large selection of marine and reef lighting replacement parts for all of your aquarium lighting needs.

We love to answer questions and help out, please just send your questions to service@oceanreeflections.com and we will get back with you soon as possible usually within a few minutes! You will find (just some) of the products we carry below if you cannot find what you are looking for there is a "VERY GOOD CHANGE" we can still get it and save you money with our low Ocean ReeFlections prices!  Please just let us know what you are looking for we would be more then happy to help out!