General Care Requirements For Aquarium Coral

Aquarium Conditions

Raising corals in aquariums takes a little more care and understanding than most marine fishes. You will need to be more cognizant of the physical, chemical and biological requirements of corals if they expect to achieve success. Lighting, water chemistry, water motion, and temperature are the primary factors of concern in maintaining living corals. Biological factors, e.g., coral aggression, corallivory, disease and competition from algae, are also important.
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    Corals are very unique animals that will make a great addition to most saltwater tanks if cared
    for properly. most corals are photosynthetic, which means they produce most of their food from
    the light All photosynthetic corals require proper lighting in able to be housed in the home aquarium. Most common lighting fixtures used for corals are fluorescent light tubes or halide bulbs, though some aquarists use led’s. when using lighting for photosynthetic corals they need certain standards.

    Corals, or more correctly their zooxanthellae, require light of the right intensity, spectrum and
    duration. Metal halide lamps and very-high-output (VHO) fluorescent lamps are popular either as the sole source of light or in combination, and are often used in conjunction with blue actinic fluorescent lamps. The lamps most used by experienced aquarists have a color temperature of 5,500-20,000°K, although some higher temperature bulbs are also in use. For additional information go to “Coral Lighting.”


    For low light needing corals it is adequate to provide about 1 to 2 watts of light per gallon of water, or for a reef tank with many varieties of corals it is best to place these types at the bottom of the aquarium.

    For moderate light needing corals it is adequate to provide anywhere from 2 to 4 watts of light per gallon of water, and usually it is best to place these corals in the middle of the aquarium.
    And for high light needing corals it is best to provide anywhere form 5 to 7 watts of light per gallon of water, preferably these species should be illuminated by halides or powerful compact fluorescents and should also be placed near the top of the aquarium.

    Water Chemistry

    There are many brands of seasalt available and most are very good at creating saltwater which is a close approximation of seawater. Fresh water to mix with the seasalt is first processed through reverse osmosis/deionizing units that are useful.
    The import aspects of water chemistry involve maintaining alkalinity, pH and calcium levels approximating those on coral reefs. These three parameters determine the calcium carbonate saturation state, which has been shown to be a control calcification.
    A variety of test kits is available today to measure alkalinity, pH and calcium in your aquarium. While these kits are not always dependable and techniques may vary, the results do give an indication if you are maintaining values close to those in nature. These test kits invariably give calcium readings in mg liter, and either degrees of hardness (dKH) or milliequivalents (meq) for alkalinity.
    The controlled addition of a saturated solution of CaOH, is capable of maintaining a calcium ion concentration of 350-500 mg liter and an alkalinity of 2.5-3.0 meq in home aquariums. But these levels may fluctuate dramatically in a small closed-system aquarium
    Water Chemistry
    Corals will survive and grow in aquariums with calcium levels less than 400 mg liter, but only when the alkalinity (carbonate hardness) is normal or high. They state that difficulty maintaining living coral occurs more often as a result of low carbonate hardness than low calcium levels. Without the addition of calcium to a reef aquarium, calcium levels will fall to about 250-350 mg liter.
    Accidental overdosing with CaOH will cause a sudden increase in pH. If this happens you can lower the pH back to normal by injecting CO] into the water. It is best to strive to maintain low levels of inorganic nutrients such as ammonia, nitrate and phosphate.
    Most hobby test kits are inadequate to detect very low levels of these nutrients (lower limit of detection for nitrate-N is about 10 mg liter, and phosphate at about 0.2 mg liter and hobbyists often report, probably erroneously, zero readings for ammonia, nitrate and phosphate in their aquariums. Corals can thrive in water with relatively high levels of inorganic nutrients but these are rapidly removed by the corals and algae.

    Water Motion

    Water motion is important for corals. A variety of submersible pumps, dump buckets, automatic siphons, and other surge generating devices are in use on both large and small aquariums with living aquarium coral.
    Water Motion

    Care Requirements For Corals in General

    Basic Facts About Corals

    • Relatively high inorganic nutrients do not appear to limit the growth of corals in aquariums.
    • Small coral colonies acclimate more successfully to aquariums than do larger colonies.
    • Corals appear to be highly sensitive to changes in lighting. What may appear to the human eye to be a subtle change in lighting, e.g., changing a lamp, may result in bleaching.

    • Most corals can tolerate exposure to air for 18-24 hours provided they remain damp.
    • Bacterial infections are common in captive corals but can often be cured with antibiotics such as chloramphenicol.

    • Rapid tissue necrosis is common among captive corals usually starting at the base of the coral and working its way to the tips of branches.

    • The addition of plankton is not required to maintain zooxanthellate corals in most Aquariums.

    • Corals that ordinarily live in turbid and virtually stagnant lagoons, e.g., Plerogyra sinuosa, will coexist in the same aquarium with corals obtained from wave-swept fore-reef environments, e.g., Acropora grandis.

    • Corals from the Caribbean and the Pacific will coexist in the same aquarium.Corals do not require the presence of any other animals in the aquarium to survive, with the exception of herbivores to control algal growth.

    • Spawning among corals in aquariums has been reported but is rare, although asexual planulation is not uncommon in corals such as Pocillopora damicornis and Tubastrea spp.

    • Brightly colored corals often lose these pigments within a week after being imported, although they may simply be masked by zooxanthellae.

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