Marine aquariums
The sea water or salt-water aquaria is a branch of hunting . It includes all activities associated with keeping and caring for marine organisms in the aquarium .
Sea water
Natural seawater is a solution of the ions of various salts ( above all table salt , magnesium sulfate , magnesium chloride , calcium chloride and sodium hydrogen carbonate ). The average salt content is around 3.4% (34 g / L), although deviations are possible in individual cases ( Red Sea up to 4.2%). For aquarium purposes, sea water is usually produced by purifying tap water using reverse osmosis and adding sea salt mixtures. Zoos and large public aquariums on the coast also sometimes use natural seawater if it is clean enough. The salt content can be checked with a hydrometer or refractometer .
Coral reef aquarium
The coral reef aquarium is the most common type of saltwater aquarium among private individuals today. Advances in understanding the coral reef ecosystem and technical advances make it possible today to bring a tiny section of the colorful world of reefs home. Fish, invertebrates and the necessary technology are sold through specialist dealers.
technology
There are several methods of running a saltwater aquarium, e.g. B. the Berlin system , Jaubert system , deep sand bed , zeolite method , sludge filter or algae refuge. They all primarily serve to break down nutrients . Filters for water treatment, such as those used in freshwater aquariums, have not proven themselves. Usually a protein skimmer and living stones take over the filter function.
All reef aquariums need strong lighting, as most of the commonly maintained corals live in symbiosis with unicellular algae , the zooxanthellae . These produce oxygen and organic compounds through photosynthesis from carbon dioxide and water, which feed the corals. Today metal halide lamps ( HQI ), optionally combined with blue T5 or T8 lights, or pure modern T5 lights are used. High-performance light-emitting diodes are also increasingly being used, both exclusively and in combination with T5 lights.
In addition, a strong movement of water is necessary, for which a wide variety of feed and flow pumps are used. The aquarium water should be completely circulated at least ten times an hour. The current is necessary so that the water diffuses through the living stones and so that the metabolic products of the sessile corals are transported away.
Coral reef aquariums should have a temperature of 24 to 28 ° C. Often the pumps and the lighting generate so much waste heat that additional rod heating is not necessary as in freshwater aquariums. In the summer months, many hard coral lovers have problems with the water temperature. It should not exceed 30 ° C. A temperature above 30 ° C has a devastating effect on the zooxanthellae. These begin to die off. Thus, the flow of nutrients to the coral polyps is interrupted and the coral dies. In the wild you can already observe this process in many coral areas. Due to the climate change, the sea water begins to warm and the corals die. What remains is a white coral skeleton.
fishes
Today, reef aquariums filled with corals mainly keep damselfish , gobies , wrasse , lyre fish , pygmy angelfish and other coral fish .
Doctor fish can only be kept in very large aquariums. The yellow sail fin doctor is particularly popular . As herbivores, they are supposed to keep the algae short, which can overgrow corals if they grow excessively. Dwarf angelfish , slimy fish and algae-eating invertebrates such as some hermit crabs and snails can keep the algae short in smaller aquariums.
Anemonefish belong to the damselfish group and are also kept frequently because of their interesting behavior. In pure fish aquariums, butterfly fish , trigger fish or filefish , which often attack invertebrates, can also be kept.
Almost all fish traded are wild-caught, caught in coral reefs. Exceptions to this are anemonefish and dwarf perch , which can be bred in aqua farms. Breeding most of the other fish has not yet been possible due to their tiny larval stages and their long, planktonic lifestyle. There are, however, some stragglers who have specialized in the breeding of saltwater fish, but the cost-benefit ratio is not worth the extra income, but it helps to reduce the number of game removals.
Invertebrates
In reef aquariums, mainly sessile cnidarians such as hard corals , soft corals , crust anemones and disc anemones are kept. Sea anemones are no longer as popular as they often wander around in the aquarium and nettle stuck invertebrates. Other aquariums suitable for invertebrates are hermit crabs , various shrimp , giant clams , brittle stars , sabellidae and Serpulidae .
Especially with the cnidarians, the aquarium enthusiast can fall back on a wide range of animals reproduced in the aquarium. Some providers have specialized in reproducing particularly colored hard corals. Some shrimp and hermit crabs can now be grown in the aquarium.
Hard coral husbandry
Hard corals are mostly reef-forming because they deposit lime. Stony corals have existed since the Paleozoic , i.e. for around 500 million years . You have played a key role in shaping our earth . Almost all hard corals live within a warm belt . The colder it gets, the fewer hard coral species you will find. Most of the time they do not grow at depths less than 50 m, as they are very light-dependent due to the zooxanthellae . Stony corals can live solitary, so to speak as a giant single polyp, or in colony form with a few to many thousands of individuals . Hard corals are sensitive organisms and not easy to care for, they are not suitable for beginners.
The tank should be very stable when stocked with hard corals and the technology should work without problems. Hard corals can therefore only be placed in a newly established tank after at least six to twelve months, whereby this must not be too dominated by soft corals . Stony coral tanks should have little fish stock so that too much phosphate and nitrate do not accumulate in the tank when the fish are fed and excreted . Most suitable for socialization are doctor fish , coral guardians , slime fish , shrimp and starfish . On the other hand, nitrate and phosphate are essential components of all living things. A small proportion must always be present, otherwise all growth would stop. The trick is to always keep these values in a reasonable relationship.
Light factor:
Especially the corals are dependent on sufficient light due to their special way of life and nutrition. They are normally supplied by algae , which are stored in their tissue and provide energy through photosynthesis . Some corals, on the other hand, prefer darkened locations because they do not eat photosynthetically, but rather eat zoo or phytoplankton . Still other animals are settled in middle-light zones, bright light would inevitably lead to the decline of these animal colonies. It is therefore very important to know the light needs of the individual animals and to satisfy them in the seawater basin.
Fish are not that sensitive. In principle, HQI lamps and T5 fluorescent tubes are suitable for a reef tank . For a pure fish tank, fluorescent tubes are completely sufficient. In the meantime, LED lighting is an attractive lighting method which, in addition to lower heat generation, also scores significantly better in terms of light spectrum and efficiency than HQI lamps or fluorescent tubes. 5 tubes are also available in a blue light spectrum to bring out the fluorescence of the corals, but with LEDs in the wavelength range of approx. 445 - 465 nm this fluorescence-promoting spectrum is generated considerably better, so that blue is introduced LED represents an innovation in saltwater aquariums.
Flow factor:
A clean circulation through cleverly installed flow pumps - every part of the basin should be flowed through at least temporarily - prevents suspended particles from settling and "going moldy". These are properly disposed of by the skimmer , the mechanical filtration and the filtering or plankton-eating organisms. In addition, the invertebrates' waste materials are washed away by them. The water surface should always be in motion so that the gas exchange over the surface works well and no scum forms on the surface. The pool contents should be circulated at least 5 to 10 times per hour. It is best to change direction with alternating pumps every 6 hours.
In order to imitate a current that corresponds to the movements of the water in the natural habitat of the animals, specialist retailers offer sophisticated pump systems.
- Powerhead pumps; Power-head pumps with filter floss as a mechanical quick filter are ideal because they are cheap and reliable. The disadvantage, however, is that the electrical system is in the water and the pumps give off heat.
- Return pumps; If you have a powerful return pump from the filter basin, you can generate enough flow through appropriate branches .
- Plastic magnetic centrifugal pumps; Modern plastic magnetic centrifugal pumps are able to run relatively quietly and with little maintenance at high efficiency. Your electrical system is outside the pool and does not give off any heat to the water.
Factor water values:
In order to be able to offer the animals conditions in which they feel comfortable, regular checks of the most important water values must be carried out. Much misfortune arises from neglect in this area. The accessories industry now offers the most important test procedures so that it is possible to identify and correct essential irregularities. If an aquarium equipped with the appropriate technology is set up and staffed correctly, a basis is created for it to function satisfactorily in the long term. The longer a marine aquarium is in operation, the greater the problems there can be with some substances. So far not all difficulties have been solved by a long way, but serious shortcomings can be avoided. The following water values will have to be measured differently, but regular checks are essential. Before the animals are introduced, the aquarium water must first be checked for suitability. The following water values are important: ammonium / ammonia , nitrite , carbonate hardness (Kh), pH value , temperature , density . Knowledge of the following substances is necessary for permanent operation: nitrates, phosphates , redox potential and oxygen . If difficulties arise and poisoning is suspected , the following analyzes should be carried out in the order given: density, temperature, ammonium / ammonia, nitrite, pH value, copper , zinc and aluminum . Treatment with copper sulfate is only useful in conjunction with a copper test. With every water test, it must be ensured that it is stored and used exactly according to the manufacturer's instructions. All measured values determined and the measures taken should be entered in a measurement report.
Other aquarium types
There are other types of seawater aquariums for keeping marine animals that do not live in coral reefs.
North Sea Aquarium
Fish and invertebrates from the North Sea are kept in a North Sea aquarium. Since they are not in trade, the inhabitants have to be caught by the aquarist themselves or obtained from fishermen. The temperature of a North Sea aquarium must be between 10 ° C in winter and not more than 20 ° C in summer. This can usually only be achieved with a cooling unit. While there are often North Sea aquariums in public show aquariums, they are very rare in private individuals.
Mediterranean aquarium
The same applies to the keeping of inhabitants of the Mediterranean . You have to catch them yourself. Here the temperature can rise up to 24 ° C in summer. There are many public show aquariums that show Mediterranean animals, but private individuals have almost completely displaced them by the more colorful inhabitants of tropical seas.
Mangrove aquarium
In the mangrove aquarium , residents of the mangrove zone are kept. The animals often live amphibiously , half on land. Mudskippers , other gobies that live in shallow water , waver and land crabs are typical residents. The aquarium can be planted with saplings of the red mangrove ( Rhizophora mangle ). This type of aquarium can also be used as a brackish water aquarium .
Aquarium for large fish
In public aquariums and zoological gardens, attractive large fish such as sharks , rays , moray eels , groupers , snappers or jacks are often kept. With very large systems, visitors can often walk through the aquarium in a glass tunnel. Considerable technical efforts are required to keep the water clean. These include very large protein skimmers , trickle filters and sand filters .
Deep sea aquarium
In a few public aquariums, such as the Berlin Zoo aquarium, you can see fish from greater depths in the world's oceans. The basins are dark or only very little lit, so that you can only see the sparkling luminous organs of the deep-sea fish . The pine cone fish that live in nature at depths of up to 400 meters are among the few that have been kept up to now. The Rotterdam Zoo has recently added an aquarium for keeping deep-sea gorgonians .
Nanorefa aquarium
This is called a seawater aquarium of small size, which is operated with little use of technology. As a rule, these are tropical seawater aquariums in which relatively undemanding marine organisms are kept. The tank sizes are usually standard aquarium sizes of 12, 20, 25, 27 or 36 liters, more rarely more or less, depending on the term nano reef defined by the individual aquarist. The term "mini reef" is also used frequently. In most cases, this designation is only a common term above 54 liters. However, some aquarists have already fallen well below the 12 liter mark. Mostly, nanorefs are set up as "offshoots" of a large saltwater aquarium in order to maintain and observe certain species which are overlooked in a normal saltwater aquarium. These nano reef aquariums originally come from North America and have enjoyed great popularity since various publications in specialist journals.
technology
lighting
Nano reef aquariums are often operated with LED lighting or small fluorescent tubes with 4, 6 or 8 watts. Other light sources are so-called compact fluorescent tubes, with the common trade name Dulux and a G-23 socket, as well as normal energy-saving lamps . The light color plays a major role here. This should be white with only one lamp. Blue light sources are suitable as additional lighting; they are not only available as fluorescent tubes, but are also available in the form of LEDs, compact fluorescent tubes or normal energy-saving lamps. The use of a reflector increases the light output. Lenses can be used with LEDs to direct the light into the aquarium.The HQI burners ( metal halide lamps ) widely used today in saltwater aquariums with the lowest power consumption of 70 watts are basically not suitable for a nano reef aquarium, as they are very high Heat dissipation and would overheat the pool.
Filtering and flow
The filtering of a nano reef aquarium with the help of aquarium filters is very limited. The biological filtering is done by bacteria in the live rock. As a rule, only a small pump is installed which, like the "big ones", circulates the aquarium at least 10 times an hour. This depends heavily on the stocking. The water circulation can also be taken over by a small filter. In the case of nanorefs, however, this only serves to filter coarse dirt and not for biological filtering. Air lifts are suitable as the second type of flow. These are more suitable for a gentler current.
Other technology
Most reports on nano reef aquariums in various media only install a pump and lighting. The lighting, regardless of the type, often makes a heating element superfluous, as the waste heat is usually sufficient. A pump also heats the water additionally. In larger nano reef aquariums, the waste heat from the pump and lighting is no longer sufficient, so that an adjustable heating element with approx. 25 watts must be installed. Another problem arises in summer, which means that another device has to be used: the nano reef is additionally heated from the outside by the increased temperatures. For the successful care of corals, the temperature must not rise above 29 ° C, not even for a short time. For this reason, a suitable fan at the edge of the pool should be directed towards the surface of the water, which takes advantage of the evaporative cooling. The evaporated water must be replaced with fresh water as often as possible. In this case, the salt content should be checked more often than usual. A small protein skimmer is only useful for nano reefs with fish stock, although it can also be replaced here by a more frequent partial water change.
literature
- SA Fosså, & AJ Nilsen: Coral Reef Aquarium , Volumes 1 to 6, Birgit Schmettkamp Verlag, Bornheim.
- Sea water atlas . 1st to 7th volume. Mergus Verlag., Melle.
- J. Ch. Delbeek, Julian Sprung: The reef aquarium . 1st and 2nd volume. Dähne publishing house.
- Daniel Knop: Reef aquariums for beginners , 2005, Dähne, ISBN 3-9351-7526-4 .
- Rüdiger Latka: The reef aquarium practice for newcomers , 2005, Rüdiger Latka Verlag, ISBN 3-9810-5700-7 .
- Ellen Thaler: Watching fish , Ulmer Eugen Verlag (1995), ISBN 3-80017-322-0 .
- Armin Glaser: Ratgeber Meerwasserchemie , 2008, Rüdiger Latka Verlag, ISBN 978-3-9810570-2-7 .
Trade journals
- Der MeerwasserAquarianer, specialist magazine for seawater aquaristics , Rüdiger Latka Verlag, ISSN 1432-1505 .
- KORALLE, marine aquarium specialist magazine , nature and animal publishing house, ISSN 1439-779X .
Web links
- Sea water wiki (knowledge database sea water aquaristics)