How to care for Corals
AQUARIUM CONDITIONS
Raising corals in aquariums takes a little more care and understanding than most of the fish you will be keeping.
You will need to be more alert to 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 a vibrant reef system. Biological factors, e.g., coral aggression, corallivory, disease and
competition from algae, are also of great importance
LIGHTING
Most corals are photosynthetic, which means they produce most of their food from
the light provided by the aquarium keeper. All photosynthetic corals require proper lighting in able to be housed in the home so it is important to research lighting
Most common lighting fixtures used for corals are fluorescent light tubes or halide
bulbs, though some aquarists use led’s which are becoming increasingly popular
Corals, or more correctly their zooxanthellae, require light of the right intensity, spectrum and
duration in order to flourish. Metal halide lamps and very-high-output (VHO) flourescent lamps are popular either as
the only source of light or in combination, and are often used in conjunction with blue actinic
flourescent lamps and LED's.
For low light needing corals it is more than enough to provide about 1 to 2 watts of light per gallon of
water, or for a reef tank with many varieties of corals you can place some of the corals at the bottom of the tank
For medium light needing corals it is enough 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 area f the tank
For high light needing corals it is good to provide anywhere form 5 to 7 watts of light per
gallon of water, and where possible these species should be illuminated by halides or powerful compact
fluorescents and should also be placed near the top level of the aquarium
WATER CHEMISTRY
There are numerous brands of aquarium salt available and most are very good at creating saltwater which
is similar to that found n nature. Fresh water to mix with the seasalt is first processed
through reverse osmosis units and can be purchased from your local lfs
The import part of water chemistry involve looking at alkalinity, pH and calcium levels
approximating those found in nature.
many test kits today will measure alkalinity, pH and calcium in your aquarium.
While these test kits are not always dependable and techniques may vary, the results do give a good indication if you are maintaining values close to those found in nature.
an addition 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 reef systems. But these
levels may go up and down dramatically in a small aquarium
Corals can survive and grow in aquariums when calcium levels are less than 400 mg liter, but only
when the alkalinity (carbonate hardness) is normal or bordering on high.
Adding too much CaOH can cause a sudden increase in pH. If this happens you can
lower the pH back to normal by injecting CO] into the aquarium
Most hobby test kits are not good enough 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 aquarium keepers
often report, zero readings for ammonia, nitrate and phosphate in their
aquariums.
WATER MOTION
Water motion is very important for corals. A variety of under water pumps, automatic
siphons, and other surge generating devices are in use on both large and small aquariums with
living aquarium coral and are a must for a successful reef system
TEMPERATURE
It is best to maintain the marine aquarium water temperature similar to that found on coral reefs, around 21°-27°
C. Higher temperatures often occur during summer months. Temperatures of 32°-35°C over a one-day period can cause corals to bleach into the tank
Care Requirements For Corals in General
Basic Facts About Corals
Raising corals in aquariums takes a little more care and understanding than most of the fish you will be keeping.
You will need to be more alert to 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 a vibrant reef system. Biological factors, e.g., coral aggression, corallivory, disease and
competition from algae, are also of great importance
LIGHTING
Most corals are photosynthetic, which means they produce most of their food from
the light provided by the aquarium keeper. All photosynthetic corals require proper lighting in able to be housed in the home so it is important to research lighting
Most common lighting fixtures used for corals are fluorescent light tubes or halide
bulbs, though some aquarists use led’s which are becoming increasingly popular
Corals, or more correctly their zooxanthellae, require light of the right intensity, spectrum and
duration in order to flourish. Metal halide lamps and very-high-output (VHO) flourescent lamps are popular either as
the only source of light or in combination, and are often used in conjunction with blue actinic
flourescent lamps and LED's.
For low light needing corals it is more than enough to provide about 1 to 2 watts of light per gallon of
water, or for a reef tank with many varieties of corals you can place some of the corals at the bottom of the tank
For medium light needing corals it is enough 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 area f the tank
For high light needing corals it is good to provide anywhere form 5 to 7 watts of light per
gallon of water, and where possible these species should be illuminated by halides or powerful compact
fluorescents and should also be placed near the top level of the aquarium
WATER CHEMISTRY
There are numerous brands of aquarium salt available and most are very good at creating saltwater which
is similar to that found n nature. Fresh water to mix with the seasalt is first processed
through reverse osmosis units and can be purchased from your local lfs
The import part of water chemistry involve looking at alkalinity, pH and calcium levels
approximating those found in nature.
many test kits today will measure alkalinity, pH and calcium in your aquarium.
While these test kits are not always dependable and techniques may vary, the results do give a good indication if you are maintaining values close to those found in nature.
an addition 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 reef systems. But these
levels may go up and down dramatically in a small aquarium
Corals can survive and grow in aquariums when calcium levels are less than 400 mg liter, but only
when the alkalinity (carbonate hardness) is normal or bordering on high.
Adding too much CaOH can cause a sudden increase in pH. If this happens you can
lower the pH back to normal by injecting CO] into the aquarium
Most hobby test kits are not good enough 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 aquarium keepers
often report, zero readings for ammonia, nitrate and phosphate in their
aquariums.
WATER MOTION
Water motion is very important for corals. A variety of under water pumps, automatic
siphons, and other surge generating devices are in use on both large and small aquariums with
living aquarium coral and are a must for a successful reef system
TEMPERATURE
It is best to maintain the marine aquarium water temperature similar to that found on coral reefs, around 21°-27°
C. Higher temperatures often occur during summer months. Temperatures of 32°-35°C over a one-day period can cause corals to bleach into the tank
Care Requirements For Corals in General
Basic Facts About Corals
- Quite high inorganic nutrients do not appear to limit the growth of corals in reef aquariums.
- Some small coral colonies acclimate more successfully to aquariums than a larger one
- Corals may appear to be highly sensitive to changes in aquarium lighting. What may appear to the human
eye to be a subtle change in lighting, e.g., changing a lamp, may result in bleaching of the corals into the tank. - Some corals can tolerate exposure to air for 18 hours provided they remain damp but it is always best to try and avoid this
- Bacterial infections are very common in captive corals but can often be cured with specially designed medications
- The addition of plankton is not required to maintain zooxanthellate corals in most
aquariums although a practice performed by many reef keepers - Corals that live in turbid and virtually stagnant lagoons.
can coexist in the same aquarium with corals obtained from wave-swept fore-reef
environments and often are kept together by reef keepers - Corals from the Caribbean and the Pacific will coexist in the same aquarium as will corals from other regions. Always research before buying them though
- Corals don't require the presence of any other animals in the aquarium to thrive, with
the exception of herbivores to control algal growth which can be problematic. - Spawning of corals in aquariums is rare
- Brightly colored corals will often lose their bright colour after being introduced into the tank. This does not mean that they are not healthy.
