 | This article possibly contains original research .(March 2012) |
Fishless cycling is a form of "maturing" an aquarium. In this process, ammonia is provided to allow beneficial bacteria to colonize. Fishless cycling can reduce the chance of fish loss resulting from insufficient populations of these bacteria.
Fishless cycling takes place over a period of several weeks, during which the aquarist provides an ammonia source for the development of the nitrifying bacterial colony. Nitrifying bacteria in the aquarium grow on all surfaces, but particularly in areas of high water flow and high surface area such as the filter. Allowing ammonia to be converted to nitrite, and on to the less harmful nitrate, minimizes stress and injury to aquarium fish. [1] [2] The "nitrogen cycle" may take several weeks to complete, but may be quicker under certain conditions. Higher water temperatures, greater dissolved oxygen and bacterial seeding from an established tank may cut down the time required to less than a week. [3]
The most significant advantage of fishless cycling is that it can reduce fish loss due to ammonia and nitrite spikes. Fish loss can be very discouraging for beginners of fish keeping, so indirectly, fishless cycling can also help beginners get a good start.
Cycling aquariums using feeder fish is risky, because it infects the aquarium with any disease or parasite they happen to have. Fish raised as feeders do not get the same degree of care as non-feeders. Fishless cycling avoids this potential problem.
Fishless cycling also allows the aquarium to be partially stocked from the moment it is cycled, if the nitrogen cycle is completed with high concentration of pure ammonia added daily. This means that for large aquariums, where fish must be added in several batches, fishless cycling is faster than cycling with fish. It can also be extremely useful when the fish keeper plan to stock a tank full of territorial aggressive fish, such as African cichlids, where the later added fish can be at a disadvantage. [4] However, care in adding ammonia for fishless cycling must be used, too high of an ammonium concentration can kill the helpful bacteria. [5]
These are not problems when ammonium hydroxide or ammonium chloride is used as the source of ammonia.
Nitrate is a polyatomic ion with the chemical formula NO−
3. Salts containing this ion are called nitrates. Nitrates are common components of fertilizers and explosives. Almost all inorganic nitrates are soluble in water. An example of an insoluble nitrate is bismuth oxynitrate.
The nitrogen cycle is the biogeochemical cycle by which nitrogen is converted into multiple chemical forms as it circulates among atmospheric, terrestrial, and marine ecosystems. The conversion of nitrogen can be carried out through both biological and physical processes. Important processes in the nitrogen cycle include fixation, ammonification, nitrification, and denitrification. The majority of Earth's atmosphere (78%) is atmospheric nitrogen, making it the largest source of nitrogen. However, atmospheric nitrogen has limited availability for biological use, leading to a scarcity of usable nitrogen in many types of ecosystems.
Nitrification is the biological oxidation of ammonia to nitrate via the intermediary nitrite. Nitrification is an important step in the nitrogen cycle in soil. The process of complete nitrification may occur through separate organisms or entirely within one organism, as in comammox bacteria. The transformation of ammonia to nitrite is usually the rate limiting step of nitrification. Nitrification is an aerobic process performed by small groups of autotrophic bacteria and archaea.
A marine aquarium is an aquarium that keeps marine plants and animals in a contained environment. Marine aquaria are further subdivided by hobbyists into fish only (FO), fish only with live rock (FOWLR), and reef aquaria. Fish only tanks often showcase large or aggressive marine fish species and generally rely on mechanical and chemical filtration. FOWLR and reef tanks use live rock, a material composed of coral skeletons harboring beneficial nitrogen waste metabolizing bacteria, as a means of more natural biological filtration.
Live rock is rock from the ocean that has been introduced into a saltwater aquarium. Along with live sand, it confers to the closed marine system multiple benefits desired by the saltwater aquarium hobbyist. The name sometimes leads to misunderstandings, as the "live rock" itself is not actually alive, but rather is simply made from the aragonite skeletons of long dead corals, or other calcareous organisms, which in the ocean form the majority of coral reefs. When taken from the ocean it is usually encrusted with coralline algae and inhabited by a multitude of marine organisms. The many forms of micro and macroscopic marine life that live on and inside of the rock, which acts as an ideal habitat, give it the name "live rock".
Nitrosomonas europaea is a Gram-negative obligate chemolithoautotroph that can derive all its energy and reductant for growth from the oxidation of ammonia to nitrite and lives in several places such as soil, sewage, freshwater, the walls of buildings and on the surface of monuments especially in polluted areas where the air contains high levels of nitrogen compounds.
The Berlin Method of biological filtration is a method for maintaining a clean and stable environment within a saltwater aquarium, typically a coral reef system. This method relies on the use of ample live rock. The theory is that aerobic bacteria covering the surface of the porous live rock and sand convert harmful ammonia into nitrites, then nitrates, which are much less harmful to the tank's inhabitants. Through the process of diffusion, the nitrates move deep within the rock where they are converted by anaerobic bacteria to free nitrogen gas. Left over nitrates are removed through regular partial water changes, or with algal filtration such as an algae scrubber. As an added measure, a protein skimmer is used to remove some of the dissolved organic compounds before they break down into ammonia, although skimmers do not remove ammonia from fish urea.
Community aquaria are tanks that are designed to contain more than one species of fish. Most commonly they include a variety of species that do not normally occur together in nature, for example angelfish from Brazil, swordtails from Mexico, and gouramis from South East Asia. The aim of such communities is to bring together fish that are compatible in temperament and water requirements, while using their different colours and behaviors to add interest and entertainment value.
Fishkeeping is a popular hobby, practiced by aquarists, concerned with keeping fish in a home aquarium or garden pond. There is also a piscicultural fishkeeping industry, serving as a branch of agriculture.
The common goldfish is a breed of goldfish and a family of Cyprinidae in the order cypriniformes. Goldfish are descendants of wild carp from East Asia. Most varieties of fancy goldfish were derived from this simple breed. Common goldfish come in a variety of colors including red, orange, red/white, white/black, yellow/white, blue, grey/brown, olive green, yellow, white, and black, with the most common variation being orange, hence the name. The brightness, duration, and vividness of the color may be an indication of the fish's health status, but not always, as water conditions and quality of care affect the fish's appearance.
Denitrifying bacteria are a diverse group of bacteria that encompass many different phyla. This group of bacteria, together with denitrifying fungi and archaea, is capable of performing denitrification as part of the nitrogen cycle. Denitrification is performed by a variety of denitrifying bacteria that are widely distributed in soils and sediments and that use oxidized nitrogen compounds such as nitrate and nitrite in the absence of oxygen as a terminal electron acceptor. They metabolize nitrogenous compounds using various enzymes, including nitrate reductase (NAR), nitrite reductase (NIR), nitric oxide reductase (NOR) and nitrous oxide reductase (NOS), turning nitrogen oxides back to nitrogen gas or nitrous oxide.
Nitrobacter is a genus comprising rod-shaped, gram-negative, and chemoautotrophic bacteria. The name Nitrobacter derives from the Latin neuter gender noun nitrum, nitri, alkalis; the Ancient Greek noun βακτηρία, βακτηρίᾱς, rod. They are non-motile and reproduce via budding or binary fission. Nitrobacter cells are obligate aerobes and have a doubling time of about 13 hours.
Ammonia poisoning is a common fish disease in new aquariums, especially when immediately stocked to full capacity. Ideally, the level of ammonia (NH3) and ammonium compounds (i.e. those containing NH4+) in fish tanks should be zero. Although trace amounts are generally harmless, they can still lead to problems over time. Understanding the nitrogen cycle is essential for the keeping of any aquatic life.
Nitrifying bacteria are chemolithotrophic organisms that include species of genera such as Nitrosomonas, Nitrosococcus, Nitrobacter, Nitrospina, Nitrospira and Nitrococcus. These bacteria get their energy from the oxidation of inorganic nitrogen compounds. Types include ammonia-oxidizing bacteria (AOB) and nitrite-oxidizing bacteria (NOB). Many species of nitrifying bacteria have complex internal membrane systems that are the location for key enzymes in nitrification: ammonia monooxygenase, hydroxylamine oxidoreductase, and nitrite oxidoreductase.
Aquarium filters are critical components of both freshwater and marine aquaria. Aquarium filters remove physical and soluble chemical waste products from aquaria, simplifying maintenance. Furthermore, aquarium filters are necessary to support life as aquaria are relatively small, closed volumes of water compared to the natural environment of most fish.
An aquarium is a vivarium of any size having at least one transparent side in which aquatic plants or animals are kept and displayed. Fishkeepers use aquaria to keep fish, invertebrates, amphibians, aquatic reptiles, such as turtles, and aquatic plants. The term aquarium, coined by English naturalist Philip Henry Gosse, combines the Latin root aqua, meaning 'water', with the suffix -arium, meaning 'a place for relating to'.
SHARON is a sewage treatment process. A partial nitrification process of sewage treatment used for the removal of ammonia and organic nitrogen components from wastewater flow streams. The process results in stable nitrite formation, rather than complete oxidation to nitrate. Nitrate formation by nitrite oxidising bacteria (NOB) is prevented by adjusting temperature, pH, and retention time to select for nitrifying ammonia oxidising bacteria (AOB). Denitrification of waste streams utilizing SHARON reactors can proceed with an anoxic reduction, such as anammox.
Recirculating aquaculture systems (RAS) are used in home aquaria and for fish production where water exchange is limited and the use of biofiltration is required to reduce ammonia toxicity. Other types of filtration and environmental control are often also necessary to maintain clean water and provide a suitable habitat for fish. The main benefit of RAS is the ability to reduce the need for fresh, clean water while still maintaining a healthy environment for fish. To be operated economically commercial RAS must have high fish stocking densities, and many researchers are currently conducting studies to determine if RAS is a viable form of intensive aquaculture.
Comammox is the name attributed to an organism that can convert ammonia into nitrite and then into nitrate through the process of nitrification. Nitrification has traditionally thought to be a two-step process, where ammonia-oxidizing bacteria and archaea oxidize ammonia to nitrite and then nitrite-oxidizing bacteria convert to nitrate. Complete conversion of ammonia into nitrate by a single microorganism was first predicted in 2006. In 2015 the presence of microorganisms that could carry out both conversion processes was discovered within the genus Nitrospira, and the nitrogen cycle was updated. Within the genus Nitrospira, the major ecosystems comammox are primarily found in natural aquifers and engineered ecosystems.
Ammonia pollution is pollution by the chemical ammonia (NH3) – a compound of nitrogen and hydrogen which is a byproduct of agriculture and industry. Common forms include air pollution by the ammonia gas emitted by rotting agricultural slurry and fertilizer factories while natural sources include the burning coal mines of Jharia, the caustic Lake Natron and the guano of seabird colonies. Gaseous ammonia reacts with other pollutants in the air to form fine particles of ammonium salts, which affect human breathing. Ammonia gas can also affect the chemistry of the soil on which it settles and will, for example, degrade the conditions required by the sphagnum moss and heathers of peatland.