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Emergency Tips For Your Aquarium

By Stan and Debbie Hauter

POWER OUTAGES:

An aquarium is safe for some time without filtration when the power goes out, but the inhabitants cannot survive for very long without oxygen. When you do not have a battery operated air pump or an emergency power source to run one to provide a steady source of oxygen to your aquarium in an emergency situation, it's easy to do so manually, and at the same time keep the water circulated.

Here's How

Take any type of clean cup, pitcher or other container, scoop out and fill it with aquarium water.
Hold the filled container some distance above the aquarium, and pour the water back into the tank. Repeat this process numerous times.
Tip: A larger volume of oxygen is generated the higher the water is dispensed from above the aquarium, and the number of repeated times this is done.

More Oxygenation Tips

There is no set rule on how often this should be done, because every aquarium is different. You'll need to judge for yourself at what intervals each hour is going to be best for your system. When in doubt, go ahead, and if the fish start coming to the surface gasping for air, it's definitely time.
To avoid messing up the substrate and stirring up a bunch of crud, particularly if you have a small or shallow aquarium, place a small plate or bowl in the tank and pour the water onto this area. Ceramic or glass items work well for this, because the item has to be heavy enough to stay submerged and in place.
If you are using the floating hot water container method to manually generate heat in the aquarium, periodically pour some of the water over the top of the containers. Remember, heat rises. Most of the heat generated from the floating containers will stay near the surface, so this is a good way to get the warm water circulated.
If your system ends up being shut off for a long period of time, due to the lack of filtration it's important to periodically test the water for any sign of ammonia. If ammonia does start showing up, you can be ready to handle the situation by having an ammonia reducing product such as Kordon's AmQuel on hand.

EMERGENCY EVACUATION:

By Stan and Debbie Hauter

When deadly hurricanes, severe flooding, or other types of threatening weather conditions are coming your way, it may be necessary to evacuate. People prepare and take with them all the necessities a family will need for the time they will be away, including their loved pets such as cats, dogs, exotic or other animals, but what do you do about fresh or saltwater aquarium pets? Should you pack them up as well? The answer is yes you can, however many things need to be considered before doing so.

Having to make the decision to leave your wet pets behind to face the elements alone is a very difficult and sad thing to have to do, because in all likelihood during extreme weather situations the power will go out, which means if you are unable to remain at home to tend to your aquarium livestock's needs, or in the worse case scenario the house gets badly damaged or even completely demolished, all can be lost.

For some people their decision has been made one way or the other, but for those that are not sure of what to do, consider the following questions when deciding on whether or not to pack-up your wet pets and go.

How much "time" to do you have to get ready to evacuate?
Do you have all emergency supplies and essential personal items for the family and none-aquarium household pets packed and ready to go?
How much "room" do you have for transporting your family, and necessities, and none-aquarium pets?
How much aquarium livestock do you have to move?
Is there enough room to include all or at least some of them?
(If you have a substantially sized saltwater tank or full-blown reef system, undoubtedly you will NOT be able to take it ALL with you. You will have to decide what you want to take, and/or have space for. When it comes to corals, stony or SPS/LPS corals have demanding lighting requirements, therefore these species will most likely not fair well during this stressful time. For this reason soft corals as the best choice, and if space is limited, just take some coral frags or cuttings instead.)
Do you have or can you get the items needed to pack-up and move your livestock in time?
How far are you going to have to travel?
How long will it take you to get there?
How long do you think you will have to be away?
Where are you going to stay?
Would the place you will be staying allow or have space for setting up an emergency type QT, to store some supplies, as well as mix up saltwater solutions for making water changes during your stay?
Will electricity be available?

Obviously if you are in a "GOTTA GO RIGHT NOW" situation, by all means don't hesitate, take only what you need and get out! For those of you that may have some time to work with, have weighed out these questions and come to the conclusion that it is "plausible" to take your aquarium pets with you, continue on to our "Checklist of Items Needed to Move Your Wet Pets Quickly".

What To Look For When Purchasing Fish

What to look for when purchasing Your New Salt water fish

By Stan and Debbie Hauter

When it comes to buying saltwater aquarium fish it is important to know what to look for when inspecting a potential new tank inhabitant. Before buying any saltwater aquarium fish there are four things you need to be sure of; that it is suitable for the level of aquarium keeping you are at, it will be compatible with your other tank occupants, it is in excellent health, and it is eating well. Aside from these consideration, keep in mind that you need to take your time and NOT BUY ON IMPULSE AT FIRST SIGHT!! It is wise to go back several times over a few days or weeks to check out a fish more than one time. Don't stop at just one store and buy. If at all possible, shop around and check out various fish stores in your area to see what they have to offer.

So, what is it that you need to look for when buying a fish? To evaluate a fish there are two basic areas of observation to look at; appearance and behavior. Look closely at the eyes, fins, mouth, skin, scales and abdomen, keeping the following points in mind when observing a potential new purchase.

Eyes
The eyes should be bright and clear and normally set in the head. Internal bacterial infections are often first seen as a gray cloudy film or light misty appearance in the eyes. A fish with sunken eyes, ones that seem to be too small for their sockets, is not a good sign, especially when the fish displays shallow breathing and little activity. This condition may be a result of exposure to a poison, such as cyanide, and its future probably does not have a sunny outlook.
Fins
The fins should be crisp and clean with no rough or ragged edges. Many times when a fish has ratted or frayed fins it may be a sign of ammonia burn from collecting, poor water quality or fighting with other fishes, which can make it an ideal candidate for bacterial infection or other diseases. The fins should not be clamped down or unable to be completely extended once in a while, as fish normally do.
Mouth
The tissues of the mouth should be firm and uninjured. An injury in the mouth area could cause lack of interest for the fish to eat and can be a potential site for fungus and bacterial infection.
Skin & Scales
The skin and scales should be smooth and well colored. Indistinct, discolored blotches on the upper sides are usually a sign of an internal disease, especially if associated with rapid breathing. Uplifted, raised or missing scales are also a bad sign.
Stomach
The stomach (or abdomen) area should be well rounded and slightly convex (curved out) in a healthy fish. As the fish looses body mass, the abdominal profile becomes straight and then concave (sunken in). The condition of the abdomen can offer clues to the recent history of the fish and some indication of how easy it will be to get it to eat. Beware the sunken stomach! Feeding is a very important sign of well being and if a fish is feed properly and eating well, the chances are that it is either in good condition or strong enough to shrug off any minor ailments or stresses of moving to a new home.

Concrete and corals?

Jerusalem Post-5/11/08

For most people, the idea of concrete blocks replacing coral reefs might seem far-fetched. But for a group of marine scientists at Ben-Gurion University of the Negev, it is just what the doctor ordered. Sturdy enough to last, yet porous enough to be implanted with corals, concrete is the basis for an innovative technique that may help save coral reefs in the Red Sea from further destruction from overzealous divers.

Photo: Courtesy

According to leading experts, more than 25 percent of the world's coral reefs have already been destroyed. The causes are varied, and they include pollution, global warming and irresponsible fishing, but another large factor is uncontrolled and careless tourism. And perhaps more alarming is the fact that although coral bleaching (the most obvious sign of sick and dying coral) has been happening since at least the turn of the last century, most of the dramatic damage has occurred over the last 20 years.

The Red Sea has a reputation for being one of the most spectacular places to dive, and Eilat attracts thousands of vacationers a year, most of whom come to dive and snorkel in the coral reefs. But the very attraction they come to enjoy is suffering from the intensive tourism, and more and more of it is disappearing every year.

According to Dr. Nadav Shashar, a marine biologist at Ben-Gurion University of the Negev who worked side by side with Dr. Faud al-Horni in Jordan on the project funded by the US State Department's USAID-MERC program, the challenge was to find a solution that would go beyond mere conservation without limiting tourism.

What the team came up with was to create specially designed concrete blocks that are implanted with real coral and are intended to attract both fish and, in turn, divers. "In the marine environment, people have tried to create artificial reefs by throwing in junk like old ships and tires, but it's like putting old train tracks in a nice, new location. People don't move in by the herds," Shashar says.

To lure both fish and divers, the unique design also had to consider a diverse array of factors - from water currents and sand patterns to size and shape. Each concrete block in the Tamar Reef, as it is called, weighs four tons. Shashar says that since their introduction near the natural reef last April, the same number of species of fish can be found in the blocks as in the natural coral. "The numbers of fish in the concrete are lower, but the divers are attracted to them, and this is an important accomplishment in preserving the natural reef."

Shashar says that there are three main innovations in this particular project. The first is the ability to build whatever size artificial reef is necessary rather than having to maintain the traditional, small structures. Second, the concrete reef is supported by a coral "nursery" so that if parts of it are lost or broken, they can be easily replaced by others that are already being grown. In the nursery, the young coral is placed in optimal conditions to encourage rapid growth, which then enables the scientists to place it wherever it is needed in the reef.

Finally, Shashar points out that until now, most of the experimental artificial reef projects have focused on conservation and not sustainability. "If you only conserve what you have and don't increase your area, it's a losing concept, because if any parts of the area are damaged, you lose it. Our challenge was to find a way to increase the area and the species to make it truly sustainable," he says.

This was made even more challenging by the fact that it traditionally takes between 80 and 100 years for coral to completely cover an artificial structure. "I don't have that kind of patience," says Shashar, whose nursery concept has reduced the amount of time it will take to just five years. Nevertheless, since its inception, 10%-15% of the coral has been lost by careless divers inadvertently knocking it down. "This is experimental, and we are still learning. The next project in Jordan, which is supposed to be planted in a few months, has a better design and is 10 times the size of the one in Israel."

Of course, this project has also attracted the attention of foreign press and scientists from around the world who are interested in emulating its success.

Shashar, who wanted to be a marine biologist since he went diving in Sharm e-Sheikh at 10, says that the idea came from two places: an emotional one as a human being and another as a scientist who believes if scientists don't lead the way in saving the coral, no one else will. "This type of project allows me to play God. With water and sand I get to create an environment that I hope will be successful ecologically. Whether or not we know exactly what we're doing is another question."

www.iui-eilat.ac.il

World's largest marine protected area created in pacific ocean

Public release date: 14-Feb-2008
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Contact: Tom Cohen
tcohen@conservation.org
703-341-2729
Conservation International
World's largest marine protected area created in Pacific OceanVast ocean reserve conserves vital resources for human well-being

Arlington, Virginia (Feb. 14, 2008) – The small Pacific Island nation of Kiribati has become a global conservation leader by establishing the world’s largest marine protected area – a California-sized ocean wilderness of pristine coral reefs and rich fish populations threatened by over-fishing and climate change.

The Phoenix Islands Protected Area (PIPA) conserves one of the Earth’s last intact oceanic coral archipelago ecosystems, consisting of eight coral atolls and two submerged reef systems in a nearly uninhabited region of abundant marine and bird life. The 410,500-square-kilometer (158,453-square-mile) protected area also includes underwater mountains and other deep-sea habitat.

Kiribati first declared the creation of PIPA at the 2006 Conference of the Parties to the Convention on Biological Diversity in Brazil. On Jan. 30, 2008, Kiribati adopted formal regulations for PIPA that more than doubled the original size to make it the largest marine protected area on Earth.

Kiribati and the New England Aquarium (NEAq) developed PIPA over several years of joint scientific research, with funding and technical assistance from Conservation International’s (CI) Global Conservation Fund and Pacific Islands Program. The CI support for PIPA is part of the Coral Reef Initiative in the South Pacific (CRISP).

“Kiribati has taken an inspirational step in increasing the size of PIPA well beyond the original eight atolls and globally important seabird, fish and coral reef communities,” said Greg Stone, the NEAq vice-president of global marine programs. “The new boundary includes extensive seamount and deep sea habitat, tuna spawning grounds, and as yet unsurveyed submerged reef systems.”

Located near the equator in the Central Pacific between Hawaii and Fiji, the Phoenix Islands form an archipelago several hundred miles long. They are part of the Republic of Kiribati, which comprises three distinct island groups (Gilbert Islands, Phoenix Islands and Line Islands) with a total of 33 islands to make it the largest atoll nation in the world.

“The creation of this amazing marine protected area by a small island nation in the Pacific represents a commitment of historic proportions; and all of this by a country that is under serious threat from sea-level rise attributed to global warming.,” said CI President Russell A. Mittermeier. “The Republic of Kiribati has now set a standard for other countries in the Pacific and elsewhere in the world. We are proud to be associated with this effort that helps the people of Kiribati, and we call on governments and private conservation groups everywhere to support Kiribati in its efforts and make similar commitments to protect their own natural systems.”

The Phoenix Islands were featured in a major article in National Geographic in February 2004 (http://magma.nationalgeographic.com/ngm/0402/feature3/).

Three NEAq-led research expeditions since 2000 found great marine biodiversity, including more than 120 species of coral and 520 species of fish, some new to science. Some of the most important seabird nesting populations in the Pacific, as well as healthy fish populations and the presence of sea turtles and other species, demonstrated the pristine nature of the area and its importance as a migration route.

Protecting the Phoenix Islands means restricting commercial fishing in the area, resulting in a loss of revenue that the Kiribati government would normally receive from issuing foreign commercial fishing licenses. NEAq and CI are helping Kiribati design an endowment system that will cover the core recurring management costs of PIPA and compensate the government for the foregone commercial fishing license revenues. The plan allows for subsistence fishing by resident communities and other sustainable economic development in designated zones of the protected area.

Keeping oceans and marine ecosystems intact and healthy allows them to better resist the impacts of climate change and continue their natural role of sequestering atmospheric carbon that causes global warming.

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Coral Spawn turns Palau Seas Pink

Coral spawn turns Palau seas pink

Article by Andrew Luck-Baker
BBC Radio 4, Palau

Dense rafts and slicks of pink coalesced all around the boat

The annual mass spawning of corals on the Palau archipelago in the western Pacific has occurred right on cue.

With Sunday night's full moon, coral polyps let forth a huge swathe of sperm and egg, to seed the next generation.

The event was short-lived - only about 30 minutes - but so vast in its scale that it turned the sea water pink.

Scientists from Palau, Australia and the UK are studying the practicality of collecting coral larvae to help restore damaged reefs elsewhere.

See what a mass spawning at Palau looks like (Reefvid.org)

As we got into the boat for our trip to Luke's reef, I admit I was not really expecting to see the mass spawning on the exact night of the full Moon.

All the visiting scientists here thought it was more likely the reproductive extravaganza would happen the next evening or the following one - based on what had happened the last two years.

The only person who seemed sure it would happen on cue was Steven Victor, the Palauan director of the Palau International Coral Reef Center. Local knowledge was spot on, as it turned out.

Almost as soon as the boat engine switched off, we got a sense that something might be brewing.

I was snorkelling in what looked like a reverse snow storm of orange and pink particles

Andrew Luck-Baker

Catching a spectacular moment

There was a faint fishy whiff in the air, and then in the torchlight, one, then two orange particles - coral spawn - suspended in the water.

Scanning from the other side of the boat, the excitement went up another notch - a steady stream of orange spat was rising to the surface in one small isolated patch.

Scuba gear was flung on and the marine biologists were overboard. I paddled on the surface with snorkel, mask and diving torch, watching the scientists check the coral colonies on the reef bed five metres below.

The minutes ticked by - lots of them. If our first stream of spawn was the warm up act, was the main attraction having a mighty tantrum and refusing to come on tonight? Apparently not. Sonia Bejarano, from the University of Exeter, UK, surfaced with an update. A great many of the branching table corals and stag horn corals - the chief reef builders - were close to spawning.

The little egg and sperm bundles were visible in the open mouths of most of the individual coral polyps of each colony.

Depending on the size of the colony, the number of tiny sea anemone-like polyps ranges from hundreds to thousands.

At 8.29pm the mass spawning began. Across the reef, polyps contracted into their stony skeletons. Spawn particles popped out of their mouths.

Because the egg and sperm bundles contain waxy yolk, they are buoyant and rise in the water column.

Within minutes, I was snorkelling in what looked like a reverse snow storm of orange and pink particles. It became thicker and thicker as more and more colonies across the reef fired their latest shots at founding a new generation.

The spawn just kept coming - the sea was becoming a pink soup. Pink was emerging as the dominant colour.

Akin to taramosalata

There was a rising pale rose particle for every cubic centimetre of seawater at least. Above water, the odour of spawn was also thick in the air - it smelt like taramosalata, the pink Greek dish made of fish roe.

I spent most of the time in a state of amazement at the surface but I managed to get down a couple of times to the reef bed to see a colony close-up as it released its spawn.

Profusions of pink blobs, each with a little tail of mucus, wafted from the antler branches of a stag horn colony.

The reef fish were also excited. Earlier most of them were hidden, lurking in dark crevices and overhangs for safety away from night-time predators. But with the spawn bonanza, many threw caution to the winds and came out to feast.

Back on the boat, Peter Mumby, also from Exeter, estimated it was about half hour from the time the first colony unleashed its spawn to the time the last one spewed forth to multiply.

The time it all started was almost exactly the same as the moment the mass spawning began the previous year he'd visited Luke's reef to video the event.

Somehow all the colonies are running with synchronised biological clocks.

A "pink soup": Scooped from the sea

In some way not really understood by scientists, they are entrained by factors such as light levels and durations from the Sun and the Moon over a year and over individual months. The result is they spawn within minutes of each other.

That synchrony is vital if you reproduce as most corals do. The majority are hermaphrodites which release their eggs and sperm into the open water for fertilisation.

The chances they will have any offspring would be terrible if they did not have tight coordination so that eggs of one colony meet sperm from another.

By now, at the surface, the number of egg and sperm bundles was staggering. Dense rafts and slicks of pink were coalescing all around the boat for as far as we could see. The ripe smell of taramosalata hung in the air.

And we could see the water below the floating spawn begin to cloud up. Seawater was penetrating every spawn particle - breaking apart separate compartments of eggs and sperm. The visibility was falling as billions of coral sperm were liberated for fertilisation.

Andrew Luck-Baker is preparing a Frontiers programme to be broadcast on BBC Radio 4 on Monday 26 May. The programme will also be broadcast on Discovery on the BBC World Service.

Rabbit fish may save the Reefs found on 120 gallons

Rabbit Fish To The Rescue Of The Reef

ScienceDaily (Mar. 21, 2008) — While rabbits continue to ravage Australia’s native landscapes, rabbit fish may help save large areas of the Great Barrier Reef from destruction.

The reason, say scientists, is the same in both cases – both rabbits and rabbit fish are efficient herbivores, capable of stripping an area of vegetation. However, in the case of the Reef, it is the vegetation that is the problem – and the rabbit fish, the answer.

“When a coral reef is weakened or damaged through human activity such as climate change or pollution or by a natural disaster like a cyclone, the coral will usually recover provided it is not choked by fast-growing marine algae,” explains Professor David Bellwood of the ARC Centre of Excellence for Coral Reef Studies and James Cook University.

“The problem is that over the years we have fished down the populations of fish that normally feed on the young weed to such a degree that the weed is no longer kept in check, it can now smother the young corals and take over. This is called a phase-shift, and the chances of corals re-establishing afterwards are usually poor. If the weed takes over, you’ve lost your reef.”

Prof. Bellwood and fellow researcher Rebecca Fox have spent recent years running live experiments to see what happens when a reef turns to weed – and which fish, if any, are of help in restoring the coral.

“To our surprise and disappointment, the fish that usually ‘mow’ the reef – parrot fishes and surgeon fish - were of little help when it came to suppressing well established weedy growth. Most herbivores simply avoided the big weeds.

“Then, to our even greater surprise a fish we had never seen in this area before was observed grazing on the weed. The rabbit fish (Siganus canaliculatus), came out of nowhere and began to clear-fell the weed placed on the reef crest.”

The rabbit fish were caught on underwater videocams, in schools of up to 15 fish, grazing the crest, slopes and outer flats of the reef, and chomping away at more than ten times the rate of other weed-eaters.

“The rabbit fish is not a fish you tend to take a lot of notice of,” Prof. Bellwood explains. “Like its terrestrial counterpart, it is brown, bland and easily overlooked – but it could be very important when it comes to protecting the GBR.”

“We hadn’t seen it previously at this site despite conducting over 100 visual censuses. This made its appearance in numbers sufficient to check the weedy growth all the more remarkable.”

However the team noticed the rabbit fish concentrated their weed-removal efforts on the crest of the reef and were less effective on the slopes and flats – a feeding preference that is yet to be explained.

In a previous study, an overgrown reef had been cleaned up by another unexpected intruder, a striped batfish.

Ms. Fox explained that the recovery of damaged reefs may depend on several different ‘guilds’ of fishes, with different feeding preferences, that will focus on particular parts of the reef and stages of the weed infestation.

For such an approach to work, however, all the various species have to be kept intact in the reef environment, ready to play their part in a salvage operation when it becomes necessary.

“In Australia these herbivore fish populations are still in fairly good shape, but around the world as the big predators are fished out, local fishermen are targetting the herbivores. In Hawaii, the Caribbean, Indonesia, Micronesia and French Polynesia there are reports of serious declines in herbivore numbers of up to 90 per cent.

“By killing them, we may be unwittingly eliminating the very thing which enables coral reefs to bounce back from the sort of shocks which human activity exposes them to.”

Prof. Bellwood says that one of the lessons from the video study is that obscure fish species may play a critical role in the survival and maintenance of coral ecosystems, and should not be overlooked. They are a key part of the resilience of the whole reef system.

“On land the rabbit is a major headache, but in the sea the rabbit fish may be an important factor in helping to keep the world’s number one tourist attraction in good shape,” he says.

Journal reference: Fox R.J. and D.R. Bellwood (2008) Remote video bioassays reveal the potential feeding impact of the rabbitfish Siganus canaliculatus (f: Siganidae) on an inner shelf reef of the Great Barrier Reef. Coral Reefs DOI 10.1007/s00338-008-0359-6

The Fine Points of Filtration

The Fine Points of FiltrationPay attention to filtration so your fish can thrive.

By Richard Harker

Maintaining ideal water conditions in a fish tank is a constant challenge. Unlike the open natural environments from which fish originate, our tanks are closed systems that accumulate waste products. As these wastes accumulate, water conditions deteriorate. This is why filtration is so important for maintaining good water quality. Filtration takes potentially harmful compounds and makes them less harmful, either by removing them from the water or by transforming them within the tank into compounds that are less potentially dangerous.

There are many ways a hobbyist can provide filtration. Broadly speaking, there are three types of filtration: mechanical, chemical and biological. Mechanical filtration traps particulate waste in some sort of material so it can be physically removed from the tank. Chemical filtration uses specialized materials or devices to remove or convert dissolved materials. With biological filtration, natural processes break down potentially harmful compounds and reduce them to less harmful compounds. Each method attacks the problem of pollutant accumulation from a different direction, so all three methods play a useful role in maintaining water quality.

Mechanical filtration

Mechanical filtration is the hobbyist's first line of defense in maintaining a healthy tank. Uneaten food, along with waste products from the tank's inhabitants, can significantly degrade water quality if allowed to remain in the tank. At first, these materials are fairly benign, but they gradually decay. As they decay, they are transformed into a multitude of organic compounds, and these are what we need to be concerned with. If there is some sort of mechanical filtration system that traps uneaten food and solid waste, and if the filter media is cleaned or replaced on a regular basis, the proportion of wastes allowed to break down declines.

Mechanical filtration can be accomplished in many ways. Most self-contained power filters include a mechanical section consisting of coarse material that traps large particles. This material is typically replaceable, so it can be periodically discarded (with some filters, it can be washed and put back into service).

Canister filters use an internal or external pump to circulate water through the filter media. The bigger canisters have upward of 25 square feet of filtering material and can process as much as 1,000 gallons of water an hour. Depending on the biological load of the system, canister filters can often handle mechanical filtration tasks for tanks as large as 200 gallons.

The key to successful mechanical filtration is regular cleaning or replacement of the filtration media. The accumulated wastes will begin to deteriorate as soon as they are captured by the filter. The more frequently the filter is cleaned, the more wastes are removed from the tank. Ideally, media should be cleaned or replaced weekly.

Advancements in LED lighting in the Reef Aquarium

Aquarium LED Lighting - A Major Advance Or Is Metal Halide Still The Light Of Choice?

Article by John Cunningham

The aquarist has had the choice of two major forms of lighting for the reef aquarium, first, fluorescent tubes, and second metal halides. Many very beautiful captive reefs have been lit using one or the other, or a combination of both. Fluorescent tubes have been used to great effect on soft coral reefs where light doesn’t need to be so powerful. Hard coral reef aquarists, however, have used metal halide bulbs because of the more intense illumination they provide. Many aquarists have supplemented this lighting with actinic fluorescent tubes for two reasons - to supply the blue light which satisfies the light needs of symbiotic algae, and to provide a light step-down system (dawn and dusk) by using timers, for the benefit of fish.

The light to be considered here in comparison to high output LED’s is metal halide. As said, metal halide is usually the light of choice for hard coral reef enthusiasts because of the high light output, and it is sometimes used on soft coral reefs. In addition to this, there are now available bulbs of 10000K, 14000K, and 20000K etc. (K = Kelvin = colour temperature.) The higher the Kelvin rating the more blue light and the cooler the colour appears.

So what’s this ‘major advance’? Metal halide is the light of choice, isn’t it?. For power output and Kelvin selectivity there isn’t a rival. That last sentence has been correct for a good while. However, there is now a rival and it looks good.

The new entrant is high power LED lighting. What is meant by high power? As I understand it, there are four LED arrays available at the moment. Two of these are rated at ‘250′ watts and ‘400′ watts, probably the most popular wattages for reef aquariums. So what? Well, there are some definite advantages to LED’s that metal halide cannot match.

To start, the LED array is contained in a rectangular box that hangs above the aquarium in the same way a metal halide would, though it could be hung considerably closer to the water surface if required. There are 25 LED’s in the array for every 12″ (the length of arrays vary from 14″ to 72″), 12 white and 13 blue (therefore the lighting colour is arranged in a similar way that fluorescent tubes would be).

The Kelvin rating of the LED’s is stated to be 20000. So it is just as suitable for corals. That is point one, LED’s equal metal halides in colour output.. So it is one all.

Metal halide bulbs need to be changed at two years (or less), to avoid light intensity reduction and spectrum shift. The LED lights can run for up to 50000 hours. Generally the ‘lights on’ period for a reef aquarium is 12 hours. This means the LED’s can run for 11 years! It is reported that there is a reduction of light intensity of 30% after that period. However, 70% light output after 11 years! If the metal halide bulb was changed every two years, five bulbs would need to be purchased - plus any supporting fluorescent tubes would need to be changed every year, so they would be changed 11 times. Two to one for LED’s.

A big problem with metal halides is the heat output. The radiated heat can and does warm up aquarium seawater. It can perhaps be reasonably argued that in cooler areas the heat from the metal halide bulb(s) cuts down on heater use. True - but what about summer, or reef aquariums in warm areas. The water heats up beyond the design temperature. If this temperature increase is regular enough and/or great enough then a chiller (cooler) is often employed. The LED unit, however, has been shown to direct heat away from the aquarium seawater. This is done by means of internal fans. The seawater is not heated up. I feel this lack of heat impact is important to the needed stability of the reef aquarium. So three to one for LED’s.

Metal halide bulbs emit UV radiation and need a UV shield to protect the corals (the corals may bleach with excessive UV). Hardly any UV radiation comes from LED’s. Four to one for LED’s.

The glitter lines produced by a metal halide bulb are very attractive and assist in making the captive reef appear more natural. LED’s also produce glitter lines. So that’s one each, five to two for LED’s.

The LED array has controls that will allow the light output to be adjusted for full sunlight, cloudy days, daylight, sunset or moonlight.. The LED bulbs can be dimmed from maximum output to zero output. Score, six to two.

Metal halides as said are able to light a beautiful reef. However, there is a cost. Electricity. Running one, two, three, or even more 150, 250, or 400 watt bulbs is expensive. The aquarist sees this when the postal service drops the bill! Included in this bill is the cost of running a chiller to control excessive heat rise in the seawater, applicable particularly in warm areas. In warm areas air conditioning may be in use, and the heat production of metal halide bulbs will not help the cost of running the conditioning. Any cost saving will be very welcome. The LED system may not be more efficient in energy usage than metal halides as far as light production is concerned.

However, it has already been mentioned that heat is not transferred to the seawater, meaning a chiller unit will not be required (unless the areas normal temperature has a detrimental effect on the seawater anyway). The purchase cost saving on a chiller is worthwhile. The electrical running cost of a chiller is also saved. Assuming that the chiller would have been in use year on year, it is significant. If air conditioning is in use, then the conditioning has to deal with the heat put into the air by the fans on the LED system. The heat production of the LED system is stated to be ½ of metal halide, therefore the air conditioning will have less work. Score, seven to two.

The cost of a decent metal halide system is reasonable, not beyond the means of most aquarists. However, (yes, here it comes) the cost of an equivalent LED system is expensive. A ‘middle’ size LED system currently can cost circa $1800. Not cheap.

However, the score might reasonably be considered as one all, as long term cost (potential electricity usage reduction, and bulb changing as opposed to no bulb changing) needs to be taken into account. So, eight to three.

To my knowledge, this is the biggest step forward in reef aquarium lighting systems for a long while, and a very exciting one. The aquarist with one of these LED units not only has a very adequate reef lighting system with a number of advantages over metal halide, but one that can be adjusted to simulate the light conditions that a wild reef encounters. In addition, in these times of environmental concern and ‘carbon footprints’, the aquarist would not only be successfully growing corals but might well be reducing the cost to the environment by using less electricity at the same time.

For any aquarist who would like to delve a little deeper, then please go to the following link:

http://www.advancedaquarist.com/2006/8/review2

Increasing Acid Could Kill Most Coral By 2050

By Andrea Thompson, LiveScience Staff Writer

posted: 13 December 2007 02:01 pm ET

SAN FRANCISCO — The world’s coral reefs face almost certain death as increasing amounts of carbon dioxide in the atmosphere are absorbed by the oceans, acidifying the water in which corals live, a new study warns.

In the past few decades, corals have come under increasing pressure from warming ocean waters, overfishing and disease. A recent study found corals in Pacific ocean were disappearing faster than previously thought.

The new study, to be presented tomorrow at a meeting here of the American Geophysical Union, points to yet another factor plaguing these underwater bastions of biodiversity: carbon dioxide.

As carbon dioxide is emitted through the burning of fossil fuels, some of it is absorbed by the world’s oceans.

“About a third of the carbon dioxide put into the atmosphere is absorbed by the oceans,” said study team member Ken Caldeira of the Carnegie Institution of Washington, “which helps slow greenhouse warming, but is a major pollutant of the oceans.”

When the carbon dioxide is absorbed in the water, it produces carbonic acid, the same acid that gives soft drinks their fizz. This acid also makes certain minerals dissolve more readily in seawater, particularly aragonite, the mineral used by corals and many other marine organisms to grow their skeletons.

The Importance of Live Rock

Many of you are probably wondering where biological filtration will
take place if there is no trickle filter. The answer lies in the live
rock. The use of live rock as a biological filter medium within the
aquarium, allows for the establishment of natural biologic processes
such as occur on the reef. These processes will become established
whenever significant quantities of live rock are used, whether a
wet/dry filter is used or not. However, a wet/dry filter can affect
the efficiency of these processes.

Live rock contains a multitude of bacteria both on the exterior and
interior of the rock, some of which are the exact same as those found
in a seeded wet/dry filter. Hence, they are perfectly capable of
nitrification. When a fish passes ammonia across its gills into the
surrounding water, or defecates, these products do not simply seek the
wet/dry filter underneath the aquarium. They are, instead,
competitively utilized by whichever organisms come in contact with
them first and considering the high velocity flow recommended in a
reef aquarium, these are usually the rock, algae and invertebrates.
Algae growing on the live rock as well as various zooxanthellae
containing invertebrates (hermatypic), will rapidly take-up dissolved
ammonia. In addition, various heterotrophic bacteria in the system
will rapidly breakdown solid wastes and numerous invertebrates will
ingest solids such as feces. In turn, if ammonia is excreted by these
organisms, it may be rapidly consumed by algae and hermatypic
invertebrates situated on the rock.

The key word here is proximity. The nitrifying bacteria, even on the
rocks, are in for serious competition for nitrogenous waste. Still,
they do get some and, like their counterparts in the wet/dry filter,
they convert ammonia to nitrite, and nitrite to nitrate while
consuming oxygen. However, unlike a wet/dry filter, the nitrifying
bacteria on the rock are in very close proximity to anaerobic areas
within the rock. For this reason, the little bit of nitrate produced
at any given time can be immediately denitrified by facultative
anaerobes in the core of the rock, where there may be plenty of
organic material to allow the process to occur completely and
efficiently. In addition, algae and corals growing on the surface of
the rock can also use the nitrate in the small pulses they are
accustomed to using. However, if the level of nitrate in the water is
too high, the system becomes saturated and these natural processes do
not function efficiently. In this situation the algae and
zooxanthellae cannot use their nitrate utilization mechanisms to pull
the nitrate level down. Still, high levels of nitrate in the water,
combined with high water flow, can create a situation where incomplete
denitrification can occur which would tend to stimulate algae growth
on the rocks; desirable or undesirable. In this situation the wet/dry
filter functions as a nitrate factory. The presence of live rock can,
however, inhibit wet/dry nitrate production either partially or
completely, depending on the bioload (animals and feeding) in the
system.

Original designs for wet/dry filters incorporated large wet sections
filled with gravel. These contained anaerobic zones which functioned
somewhat like live rock because of the proximity to the aerobic
nitrification, but were a drag on the oxygen content of the water as
they became progressively clogged with bacterial detritus and soon
became nutrient sinks which could stimulate undesirable algae growth.
These wet beds clogged and needed periodic cleaning, even when good
prefiltration was employed, since the bacteria in the dry and wet
sections continuously sloughed off a refractory organic detritus. For
this reason, recent wet/dry filter designs have smaller wet sections,
typically with easy to service media such as foam cartridges. If the
wet section can become a nutrient sink, then it follows that the live
rock could do so too, and in fact they do. However, the rocks are not
in a position where they act as a continuous mechanical filter, as the
media in the wet section is, so they do not clog. On the contrary,
numerous boring organisms within the rock continually spew forth
detritus loaded with nutrients which should be removed periodically
from the system, either by siphoning or via the prefilter.

Bearing all this in mind, a reef aquarium can operate beautifully with
or without a wet/dry filter but there are many variables that can
affect the level of success achieved. Above all, limiting the sources
and storage zones for nutrients is a general means of keeping the
system operating properly whether a wet/dry filter is used or not. One
can see, for instance, how important a piece of equipment a protein
skimmer really is as a complement to the wet/dry filter. In removing
nitrogen rich compounds before they are broken down, the protein
skimmer lowers the wet/dry filter's potential production of nitrate.
It's value is not lost in systems without a wet/dry filter either.
This is why most hobbyists running their aquaria with skimmers only,
consider skimming an essential element for long term water quality.