Water Works Wonders

Proper lighting in a reef tank is one of the most important determinants of whether the tank succeeds or fails. If there is too much light, algae will take over the tank and throw it out of balance. Too little light will make the coral pale and suffer. There are many different light systems advertised in the market today, including both fluorescent and incandescent. Spending time upfront before you add your corals to your tank will save you great expense and grief down the road.

Many corals use the “farming” method of eating. They grow algae in their tissues to harvest as food. This is a symbiotic relationship. The algae provide the coral food and oxygen and the coral provides the algae food from its wastes. These algae thrive and multiply through the process of photosynthesis- they harvest energy from light and turn it into chemical energy which the algae can use to expel oxygen. Photosynthesis requires adequate light and reef tanks that contain these “farmer coral” need to adjust the lighting so there is enough for the symbiotic algae but not enough to allow an algae bloom to get out of control and choke the tank.

The symbiotic algae contain pigments called chlorophyll “A” and “C”, which take in blue and red light for photosynthesis. Many reef aquarium lights will appear purple because they are a combination of red and blue lights.

The intensity of lighting is important as the wrong intensity can inhibit and eventually kill the symbiotic algae. The minimum light required is called the compensation point. This is the point where the oxygen that gets produced by photosynthesis is equal to oxygen requirements of the algae. Any less and the algae cannot effectively feed from the coral’s waste products. At the other end of the spectrum is the saturation point- the point where any further increase in light does not help speed up photosynthesis. Lighting in a reef tank must be maintained between these two points to keep the algae and the coral healthy.

The least expensive lights for the reef aquarist are regular 48 inches long fluorescent lights. Generally, six of these will be required- four “daylight” tubes and 2 Actinic tubes that produce blue light. They will have to be changed out every six months or so. Even though they will still seem to be bright to your eyes, the intensity drops over time. If you leave the lights in too long, you may notice damage to your corals. Compact fluorescent lights (CFL’s) are recent additions on the aquarium supplies market. They take up less space and give more output. You may consider these for a smaller tank space. In any case, the lights should be no more than four inches above the surface of the water. There are many reasons to not use standard incandescent lamps. The most important one is that they do not produce light in the correct spectrum for the algae. They also produce substantial heat which can heat the tank to dangerous levels. The final reason not to use them is the cost. Incandescents need to be replaced more frequently than fluorescents and cost far more over the life of the bulbs.

Lighting your reef aquarium is not difficult but it can be one of the more expensive parts of your aquarium and does take some time and planning upfront to keep your coral and fish happy and healthy.

If you are going to use live coral in your aquarium instead of the white, bleached coral, it should not be treated, bleached, or cured in any way, which of course would kill it. It should be handled just like a live fish, and may be taken directly from the ocean and placed in the aquarium.

While en route from the ocean to your home the coral should be kept shaded and in clean sea water, with aeration if needed. When it is placed in the tank, sufficient fresh sea water should be added to insure the health and proper chemical balance of the water. Sea water varies greatly with each location; so when gathering live coral for your aquarium it is best also to bring back enough fresh sea water to fill the tank, if possible. Remove any slime from the aquarium, if any is present, after you place the corals in your tank.

The slime can easily be taken out with a fine mesh net or siphoned out with a plastic hose. Live coral should be watched closely the first few days, and if it appears to be dead and is turning white it should be promptly removed. If you are not certain that it is dead, place it in a fish bowl or other container of sea water and observe it for a few days.

Although the distribution of live coral to aquarists away from the ocean is limited, it is can shipped by air and small heads up to six inches across, complete with live tube worms, may be ordered from collectors.

A few choice pieces of coral and a shell or two, if properly selected, will give the aquarium its basic beauty. Avoid loading your aquarium with excessive coral as this may cause much trouble. Chosen wisely, it will enhance your aquarium and even without fish, the salt-water aquarium artistically decorated with beautiful coral is a magnificent thing. When properly lighted it will handsomely decorate the finest of homes. The coral should be arranged so that it will provide hiding places for the fish so that they will feel secure. Rather than crowd the tank too much with coral, a few well chosen shells will furnish a snug, safe home for your fish. One or two choice pieces of coral, with a shell or two, should be sufficient for most aquariums, depending on the size of the tank. Then it will be a simple matter to siphon out uneaten foods without disturbing the fish.

All coral, shells, etc. must be absolutely clean and sterile before placing in the aquarium. Just because an object is snow white does not mean that it is clean. Coral should be soaked in fresh water at least two or three weeks before use. Then it should be rinsed thoroughly and if completely free of decaying odor, it may be dried, preferably in the sun. Then it may be used but with discretion. If your first aquarium was a failure it was probably due to improperly cleaned coral. Coral taken directly from the sea must be cured much longer. A minimum safety time would be from one to three months or longer depending on the size and type of coral being cleaned.

The only type of shells which should be used are shallow clam shells. These are quickly cleaned and seldom cause harm. The baby giant-clam shells of the Tridacna family are ideal as they make perfect homes for the marine fish. Pushed part way into the sand, they will leave several openings for the fish to enter or escape and it will furnish them with a dark, snug home. These shells may be obtained in any size, from an inch and a half to several feet long so they will fill the needs of any type specimen.

The best coral to use is the Staghorn, Elkhorn, Lace, or Cluster coral as these types are usually available and they are easily cleaned. They come in a wide variety of sizes and shapes and will fill nearly every aquarium need. The cluster coral is white with a beautiful brown base and it makes an attractive combination. Most of the corals will be snow white, when cleaned, with the exception of the Organ Pipe coral which is brick red. This type of coral is much in demand for it gives the desired color to an otherwise all white display. It is constructed of tiny hollow “pipes” which gives it an interesting appearance . However, because of its construction, it should be used with caution. Not more than one or two pieces should be used in the aquarium and these must be soaked and washed for at least a month to be certain that ail decayed matter is removed from their interior. This type of coral is relatively soft so that it can be easily hollowed out with an ordinary table knife, to make superb homes for your salt water pets.

Lettuce coral, Brain coral, Rose coral, etc. also may be used and they are extremely beautiful and interesting. However, because of their dense structure, they are quite difficult to cure and to be safe, they should be soaked in fresh water for at least six months before use. Then they must be inspected closely for decay and if there is still a foul odor present, they must be soaked even longer. The author has cured some exquisite specimens of Brain coral for as long as two years before finally considering them safe for the aquarium. Don’t let this discourage you however. If you have a favorite piece of Lettuce or Brain coral and would like it for your aquarium, by all means cure it! You can always set up your aquarium with one or two smaller pieces while waiting for it to cure. But don’t take a chance on it and put it in your marine aquarium until it is absolutely spotless and free from odor. You may lose your entire display.