The term "Aquarium" comes from the Latin word "aqua" meaning water and "rium" which means place or building. An aquarium (plural aquariums or aquaria) is a transparent container of either glass of high-strength plastic that nestles aquatic flora and fauna. The creatures usually include fish, invertebrates, amphibians, marine mammals and reptiles. Aquarium keeping is not just an interesting pastime but also a very popular hobby world over. It is not hard to believe that there are over 60 million enthusiasts worldwide!
Modern form of aquarium was first developed in 1850s. Since, then aquariums have come a long way. However, the history of aquariums or fish keeping can be dated back to the times of Sumerians who kept fish of wild in ponds before they were consumed for a meal. Similarly in China, they started breeding carp into koi and goldfish over 2,000 years ago. Gold fish were kept indoors in ceramic bowls in China during the song dynasty. We can also see aquarium of sorts in the ancient Egyptian art, depicting oxyrhynchus kept in rectangular temple pools.
Fish keeping became a rage as a hobby only after the Great Exhibition of 1851. Aquariums instantly gained huge popularity all over Britain and Germany closely followed suit. The modern aquariums became immensely popular world over after the First World War. Modern aquariums include sophisticated lighting and filtration systems to keep the fish healthy. The public aquaria replicate the home aquarist's hobby in a luxurious way. For example the Osaka Aquarium in Japan holds 5,400 cubic meters of volume and over 580 aquatic species.
As an aquarium keeping enthusiast you can choose to keep a simple bowl with a single fish or a complex ecosystem that includes carefully crafted support system. Your aquarium could be a fresh water or salt-water aquarium or depending on temperature it could be a tropical or cold-water aquarium. These different types of aquariums will have different kinds of fish, inhabitants, plants etc.
Most of the aquarium inhabitants are collected from the wilds though many of them are now being bread in captivity especially for aquaria. It is very important to maintain a tank ecology in such a way that it replicates the natural habitat of the tank inhabitants. For examle, factors like species selection, biological loading management, good physical design and more should be considered. Controlling water quality is also very important. It includes managing inflow/ outflow of nutrients and waste, nitrogen cycle management, beneficial bacteria population maintenance and more.
From the outdoor ponds and glass jars of antiquity, modern aquaria have evolved into a wide range of specialized systems. While fresh water aquariums are more popular owing to their low cost and easy maintenance but salt water aquarium are fast gaining momentum.
Fresh water aquarium typically include a filtration system, an artificial lighting system, air pumps, and a heater. Many a times freshwater tanks also use powerheads to increase water circulation. Besides there are physical characteristics that are integral part of its design, such as size, lighting conditions, density of floating and rooted plants, placement of bogwood, creation of caves or overhangs, type of substrate, and other factors like aquarium's positioning within a room. All these factors compound together and affect the behavior and survivability of tank inhabitants. Water quality paprameters sich as nutrients, waste, nirtogen, pH, beneficial bacteria population, water hardness, dissolved organic content, temperature, internal water pressure and more also need to be monitored.
The filteration system is very important part of aquarium and is vital for healthy maintenance. A typical aquarium filteration system includes:
- Intake Tank
- Outflow Tank
- Mechanical filteration
- Activated Carbon filteration
- Biological filteration
These filters are responsible for removal of potentially harmful nitrogenous waste, phosphates, protein build up, particulate matter and other waste from the water. It also helps in maintaining the salinity of the water. Maintenance of salinity is especially important in case of fresh water aquariums. These filteration systems are product of careful engineering. Most of them use pump to remove portions of water into an external tank where the filteration would occur. Then the filteration is carried out and at last the filtered water is returned back to the aquarium.
Though the newer and more sophisticated filteration systems also work as air pumps, they are still used to adequately oxygenate or provide carbon di oxide to the water. Aquarium heaters are designed as thermostats to regulate water temperature. Coolers are also available for use in cold water aquaria or in parts of the world where the ambient room temperature is above the desired tank temperature.
The physical characteristics are also a very important part of aquarium design. It includes factors like size, lighting, positioning in the room, density of floating and rooted plants, placement of bogwood, creation of caves or overhangs, types of substrates and more. These factors affect the behavior and survivability of tank inhabitants. The aquatic ecosystem is very delicate. There are factors we might not think to be very important but might affect the health and behavior of the aquarium ecology immensely.
The water chemistry is the determinig factor in the types of inhabitants and their health. This is the reason why most of the public aquaria with large water needs often locate themselves near a natural water source such as a river, lake, or ocean in order to have easy access to large volumes of water that does not require much further treatment.
Salt content or salinity is the most important aspect of water chemistry. A freshwater aquarium replicates a river or freshwater lake environment. Thus, it should have a salinity lower than 0.5%. Whereas, the salt water aquarium represents tha ocean, sea or salt lake environment. Thus, it should have a salt level of 5% to 18%. There are aquariums that resemble the ecosystems of estuaries where the water is brackinsh. Such aqauriums must maintain a salt level of 0.55 to 5%.
Besides salinity the pH of water is also an important consideration. Then there could be aquariums specific for soft and hard water. Dissolved organic content also affects the aquarium ecology. Also, there are a few secondary water characteristics that affects the inhabitant type and their general health. First one is the temperature. Tropical or warm water aqauria have an average temperature of about 25 degdree celcius. This temperature makes it more convenient and commonly used aquarium. However, there are variety of fish that thrive better in cold water so, to keep such fish you need to have a cold water aquarium. Water flow is also very important secondary water characteristic. While the water temperature is maintained by the thermometer/
heater unit, water moment is controlled by powerheads and thoughtfully done internal water flow. You also need to take care of internal water pressure.
Keeping aside all the ecology factors, while selcting species for the aquairum you also need to decide whether you want a community, aggressive or species tank. The species aquarium has fish from only one species and a few plants that are part of its natural inhabitant. Community aqaurium is the most common type. It has fish that might originate from different geographical locations but come from same similar water conditions and are not aggressive to each other. In an aggressive aquarium, limited number of species are kept and these species can be aggressive towards each other but are able to stand the aggression well.
There are yet another special type of aquariums that are called Ecotype or ecotope aquaria. They try to incorporate specific ecosystem found in the natural world. Thus, they include not just fish but also invertebrate species and plants found in the particular ecosystem, which the tank replicates. This is further enhanced by the water conditions and decorations. Most avid aquarium hobbyists use this type of aquaria to adorn their home and office interiors. Moreover, it also enhances the longevity of the inhabitants.
There are some special types of salt-water aquaria such as a reef aquarium. It simulates the complex ecosystem of reef present in the warm tropical oceans. They feature the diversity of the small fish and invertebrate species. It needs maintenance of sea anemones with an addition of corals, live rock, mollusks and crustacean. This type of aquarium is most difficult to maintain and requires not just special equipments but also special expertise. Moreover, they also mean higher investment. But all said and done all this effort and high investment would ultimately mean some breathtaking results and great satisfaction for the aquarium hobbyists and lovers.
Whatever type of aquarium you may choose to have one thing should be remembered and that is: an ideal aquarium ecology closely reproduces the delicate equillibrium found in nature. It might be difficult, rather virtually impossible to develop this fine balance (predator-prey relationship cannot be achieved) yet the more efforts you put in higher will be the longevity of the inhabitants. Also, prefer to have a larger tank since, they are more stable and require less attention to maintain the equillibrium.
Aquarium Ecology
Nitrogen cycle in an aquarium
The aquarium inhabitants excrete nitrogen waste that can become toxic for them if not removed from time to time. The bacteria, fungi, and some invertebrates excerete waste in form of ammonia that converts to ammonium in water. It then passes on into the nitrogn cycle. It is also produced because decomposition of plant and animal matter. However, if you add a few speies that metabolize the nitrogenous waste such as nitrifiers bacteria (nitrosomonas), they take in ammonia and metabolize it into nitrite which is then converted into nitrate by the nitrospira bacteria. You must add this knowledge to you aqaurium hobby skill. Besides bacteria having good number of aquatic plants also ensures elimination of nitrogen waste while building the biomass.
It is difficult to monitor and maintain essential bateria population. This is where the aquarium filters help. For keeping the nitrogen waste away from the aquarium you must add active carbon and biological filter to it.
Besides nitrogent cycle there are several other nutrient cycle that goes within the complex ecology of the aquarium. The dissolved oxygen enters the system at the water-airintephase surface due to the action of air pump. At the same time carbon dioxide escapes the system and goes into the atmospheric air. Then there are phophate cycle, sulfur, iron and other micronutirent cycles that are equally important. Biologial loading is often required to keep these nutrient cyles in close equillibrium.
Biological loading is the burden placed on the aquarium ecosystem by the inhabitants. If the biological loading is high the ecology gets complicated and can be easily disturbed. This is further accelaratd by the size of the aquarium. This is so because the surface area of water exposed to th air would affect the amount of oxygen intake, physical space will limit the capacity of nitrifying bacteria moreover only a few species of plants and aquatic animals find suitable home in small aquariums.
Freshwater Aquarium Vs. Saltwater Aquarium
Though most of the hobbyists prefer fresh water aquarium over saltwater aquarium, there are some that get mesmerized by the whole lot variety of colorful fish that inhabitat saltwater. Once they have tasted the pleasure of freshwater, many people like to move on with saltwater aquarium, be it an only fish or reef tank. There are a few things that keep saltwater aquaria from reaching the popularity of freshwater aquaria are that it requires bigger tank, the fish are weaker, more amount of work is required and the prie of maintenance be it of fish or equipment, is very high. The saltwater maintenance cost is highger because it is very diffiult to maintain its delicate ecosystem. However, for an enthusiastic hobbyist here are a few suggestions on how to convert a freshwater aquarium into saltwater aquarium.
- Replace the gravel with calcareous material like crushed coral, dolomite and argonite. It buffer's water and produces a stable environment.
- Make sure that your equipment does not have any metallic component because the saltwater would rust it.
- Though filtration sytem used in freshwater aquarium can be used as it is, in saltwater aquarium still you can consider getting it upgraded so that some more circulation is added so that the surface is disrupted.
- Lighting used for freshwater system works well for a "fish only" saltwater system. Therefore, you'll need an upgrade if you consider keeping invertebrates as well.
- One thing that needs to be replaced is the fish food. You have to use a combination of fresh, frozen and live food in case of marine fish. The flake food should not be major portion of fish's food.
- When you are ready for the final replaement, change water and add fresh water that is free of nitrates so that algae problem is reduced.
Both freshwater and saltwater aquaria have their own pros and cons while the former is easy to maintain and less expensive, the latter holds the excitement of fish and aquatic life in vibrant colors and captivating forms.
