Marine aquarium

From Freepedia

A Marine aquarium is an aquarium that keeps marine plants and animals in a contained environment. Marine fishkeeping is different from its counterpart freshwater fishkeeping in several important aspects. There’s more scientific bias in marine fishkeeping, the hobby of which is a large contributor to the vast scientific knowledge shared with the hobby.

Contents

Marine fishkeeping history

The very first saltwater tanks were glass jars where the romans kept anemones outside but were very short lived. The first personal saltwater fishkeeping began on a wider scale in the 1950’s, starting with the basic rectangular glass aquariums (usually 20 gallon), still popular today. Bleached coral along with a substrate of coarse crushed coral was the norm. Algae, including beneficial such as coralline, were viewed negatively and generally removed. The clean, sterile tank was viewed as the healthiest.

During the beginning days of marine aquaria, saltwater was initially collected at local beaches. Natural saltwater contains many unwanted organisms, along with the occasional unwanted pollutant. Aquarium literature of the time suggests that the most commonly kept marine fish of the day were the Percula Clownfish, Sergeant Major Damselfish, small, brackish puffer and scat, Jeweled Blennies, Sailfin Mollies, and Blue Damsels. Aquariums were equipped with large air compressors, and were heavily aerated and filtered (primarily with undergravel filters, a norm for some time).

Later in the hobby, air driven, counter-current protein skimmers were invented and revolutionized in Germany along with the Eheim pump company. Perhaps the largest revolution in fishkeeping was a more reliable submersible electric heater, invented by Eugen Jäger. Even today, Jäger is still a major company in aquarium heating.

Various initial aquarists attempted to find the chemical properties of sea water and mix in necessary trace elements to create synthetic salt mixes. Perhaps the first and undoubtedly the largest synthetic sea salt company was Instant Ocean. This revolutionized marine fishkeeping in landlocked areas instead of restricting it to areas near sources of seawater.

Various advancements in filtration included the trickle and hang-on filters, both allowing a more natural equilibrium to the aquarium environment. The advancement of fluorescent lighting technologies into higher outputs along with Metal Halide lighting established the reef tank, making it a possible to keep corals and invertebrates without natural sunlight.

More efficient chemical testing and more advanced knowledge allowed aquarists to have an idea about the chemical conditions and properties of aquariums. The biological establishment and understanding of maintaining an artificial ocean environment brought more successful and widespread marine fishkeeping. In the 1980’s, the multitude of aquarium publications had greatly increased, and general chemical and biological knowledge was more widespread.

Modern fishkeeping

Marine Aquarium Components

The major components of a Marine Aquarium are a tank, usually composed of glass or acrylic, a stand, components necessary for chemical, mechanical, and biological filtration, lighting, and an apparatus used to heat the aquarium, usually an aquarium heater. Marine Aquariums can range anywhere from a tiny, nano reef aquariums to gigantic aquariums in surplus of 300 US gallon (1200 L). Nano tanks are usually between 2.5 and 20 US gallons (10 and 80 L), though some definitions include tanks as large as 30 US gallons (120 L). These tanks are difficult to maintain due to the highly variable chemical properties of saltwater. It is usually easier to make mistakes with a highly concentrated body of water. However, large tanks, on the contrary, while easier to maintain on the biological and chemical level, are usually a financial impossibility for most individuals. For this reason, most saltwater tanks are between 40 and 100 US gallons (160 and 400 L). The stand is usually made of wood: fish tanks filled with water are extremely heavy and need a very sturdy base (a 75 US gallon aquarium filled with water and substrate can weigh in surplus of 600 US pounds).

The new age of fishkeeping focuses on various components functioning in order to create a biologically stable environment. There are various orthodoxies of fishkeeping today. The basic varieties of tanks are Fish Only (FO), Fish Only with Live Rock (FOWLR - arguably the most popular) and the reef tank, containing corals, sea anemones, or other delicate invertebrates, using high powered fluorescent or metal halide lighting fixtures in order to acquire the needed light output.

Live Rock

Live rock is rock that has been in the ocean, composed of limestone and decomposing coral skeleton, usually around a coral reef such as those around Fiji, and is usually covered with beneficial algae, coralline and tiny invertebrates and bacteria that are desirable in the aquarium. Some examples of the microfauna commonly found on live rock are crab, snail, feather dusters, brittle stars, sea stars, limpets, abalones, and an occasional sea urchins, anemones, coral, and sea sponge. Bristleworms are also used, most of which, while unattractive, are not harmful, and are useful scavengers; some species can be pests, however. The addition of live rock is one of the best ways to ensure a healthy aquarium, as the rock provides a buffer for good pH (8.0-8.3), alkalinity, and acid-neutralizing capacity. Alkalinity is often known by a rather confusing term, "carbonate hardness", or KH.

The microfauna found on live rock are detrivores and herbivores (as they eat algae and fish waste), and provide fish with a natural, attractive shelter. It usually arrives from online dealers as "uncured", and must be quarantined in a separate tank while undergoing a curing process. Live rock that is already cured is available at most pet stores that cater to saltwater. Live sand is similar to live rock and is equally desirable.

Filtration

There are a multitude of filtration methods available to the modern aquarist. All methods use a combination of chemical, mechanical, and biological filtration. Common hang-on filters usually only offer chemical and mechanical filtration (through mesh and carbon, which is not enough for the saltwater aquarium, although some hang-on filter's have plates where bacteria can colonize and provide biological filtration as well. These plates should never be cleaned, as this would kill the bacteria colonies. Most filters are marked to provide which forms of filtration they accommodate.

Depending on what is in the tank, protein skimmers are also very useful in the reef tank. With a low bioload (not many animals in the tank) and hardy livestock, a protein skimmer may not be absolutely necessary, though it is never a detriment. A heavily stocked tank, corals, and other delicate animals may need a protein skimmer to survive.

Perhaps the most popular and widespread biological filter is the refugium. Water is drawn from the main tank to the refugium (usually a smaller container hidden behind or below the main aquarium), then is returned to the main tank. This smaller tank serves two purposes: it adds water volume (thus diluting any chemical problems), and it provides a place for biological filtration. Refugiums can also serve as a temporary shelter area for recovering injured fish, delicate animals that need to be slowly acclimated to the aquarium environment, and to temporarily separate fighting inhabitants. Refugiums often contain live rock and live sand, macroalgae, and scavenger microfauna such as micro brittle stars, tiny sea stars such as asterina, snails, and worms. Some people also use refugiums to raise tiny brine or mysis shrimp for delicate fish like seahorses and dragonets. A sump is a refugium that also contains the main aquarium's other equipment, to keep all hoses, filters, and heaters out of view. This is especially common for show tanks and reef tanks.

Lighting

Lighting is a controversial topic in fishkeeping. Most fish aren't particular about lighting - the light is more for the aquarist than for the fish, though a cycle of light and dark, simulating day and night, is beneficial for fish, since it establishes a routine, and makes them feel more secure. Any light will do for an FO tank. A FOWLR tank will need a more powerful light, however, since algae and coralline need light to grow. There are many types of lights available; generally speaking, the higher the power rating, the better. Some types include fluorescent, VHO fluorescent (Very High Output), and metal halide. A powerful fluorescent lightning fixture may be enough for a FOWLR system. Coral reefs require very powerful lights and specific spectrums; research of particular species' needs before buying is essential. Metal halides seem to be the most popular lighting fixture of reef aquariums.

Heating

Most fishkeeping is tropical, and most fish gathered are caught in Africa, Southeast Asia, and the Red Sea. A temperature of 75 degrees Fahrenheit to 82 degrees Fahrenheit is the most common, reflecting the environment of the organisms. This necessitates the use of a heater, almost always fully submersible. Cold water marine fishkeeping is generally only regional, and most cold water fish are caught locally. This is because the physical appearance of cold water fish is not as attractive or colorful as that of their warmer-water counterparts.

Water Testing

A test kit is a valuable tool in fishkeeping. The most common things to test for in a saltwater aquarium are: specific gravity (often erroneously called "salinity", which is a different measurement) - usually between 1.020 and 1.025 for fish, and 1.023 and 1.025 for invertebrates and corals; pH - between 8.0 and 8.3 (can be raised with a commercially available buffer); carbonate hardness (KH) - between 8 and 12 (measures the trace elements and minerals in the water - raised by pH buffer); the ammonia cycle - ammonia, nitrite and nitrate.

While fish waste (urine and feces), and decaying matter release ammonia, the majority of ammonia (approximately 60%) in both marine and freshwater aquariums is excreted directly into the water from a fishes' gills. Biological (bacterial) nitrification converts the ammonia into nitrite ions, NO2-, and then to nitrate ions, NO3-. Nitrate is readily taken up and assimilated by algae and hermatypic corals. Some nitrate can be converted by an anerobic bacterial process to free nitrogen, but this process is very difficult to maintain. Most nitrate, which is non-toxic to fishes and most invertebrates just accumulates in the water. Ammonia and nitrite testing should be a common practice, always test to be zero, but nitrate, while extremely toxic in freshwater aquariums is not usually toxic at the levels encountered in marine aquariums due to the extremely high levels of chloride ions, Cl-. It's normal to have a little nitrate buildup, and some livestock handle it better than others. Most hermatypic corals, while able to assimilate nitrate, cannot be expected to perform well with chronically high nitrate concentrations (>40 mg/L as nitrate ion (~ 10 mg/L nitrate-nitrogen)).

Other tests may include testing for calcium, iodine, and other trace minerals. Research the particular species you wish to keep to see if it is necessary for you to do additional testing.

Water changes

Water changes are a staple of good saltwater maintenance. It involves removing 10 to 20% of the water in an aquarium, and replacing that water with pre-mixed saltwater. For instance, with a ten gallon tank, mix one or two gallons or water in a container with a synthetic saltwater mix, like Instant Ocean. Checking with the local utility company to see what one's tap water contains is often necessary for success. In almost all places, tap water will be too contaminated with chemicals and purifiers to be used in the saltwater aquarium. One will most likely use distilled water instead. Look for water made using a reverse osmosis (RO) process. With the process of allowing the salt water to mix completed (usually occupying the better part of a day); the second step in the process is to replace the water taken out of the tank with the new, mixed saltwater.

Obtaining of Marine specimens from their natural environments

Marine animals today are nearly exclusively caught in the ocean, and such activity has brought controversy. Common practices of collecting fish may involve cyanide, which destroys and poisons reefs; however the use of cyanide is small and generally portrayed out of proportion. The collection of marine animals has also become a profitable industry for some Southern Asian and African countries.

Commercial Front

Various businesses have brought a commercial front to fishkeeping, perhaps the largest being Marineland, Inc. Along with movies such as Finding Nemo, fishkeeping is becoming much more widespread than ever before. Perhaps the biggest turndown in fishkeeping is the initial costs. A 100 US gallon (400 L) reef tank full of coral and equipment often costs upwards of $5000 US. Aside from the difficulty, this is a large factor as to why freshwater fishkeeping is still so widespread in comparison to its marine counterpart.

References and further reading

  • The Conscientious Marine Aquarist, by Robert Fenner
  • Invertebrates: A Quick Reference Guide, by Julian Sprung
  • Corals: A Quick Reference Guide, by Julian Sprung
  • Reef Invertebrates: An Essential Guide to Selection, Care and Compatibility, by Anthony Calfo and Robert Fenner

External links

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