Starting with a Marine Tank

Whether you see them in  your local aquarium store or public aquaria, on a diving holiday, on TV, or  more recently at the movies an aquarium housing some of these outstanding  creatures would make a welcome addition to the homes of many people. However it  is very demanding and quite expensive to look after these wonderful animals  properly. Beginner fishkeepers really should get used to looking after tropical  freshwater fish or goldfish first before moving onto marine fishkeeping. However  for aquarists with fishkeeping experience a marine aquarium is a stunning and  rewarding addition to their home.

The principle reason  marine fish are so much more of a challenge to keep than their freshwater  cousins is to do with the complexity and stability of the seawater they live  in.

Because the sea is such a vast body of  water its characteristics hardly change at all, so marine fish are far less  forgiving of changes in the water quality than their freshwater relatives. So  proper management and regular testing of the water is essential.

Another reason these  creatures pose such a challenge is that many marine fish have very specific  feeding requirements. For example many species of coral reef Angelfish feed  only on certain species of sponges, Seahorses often feed readily, but are such  poor swimmers that they need to be kept on their own or they cannot get to  their food in time. Many types of marine invertebrate filter feed material out  of the water and certain corals need light to allow algae in their tissues to  grow.

Marine fish are considerably more  expensive than most freshwater ornamental fish because most of them are caught  from the wild .The costs involved in managing wild capture and transport of  these fish makes them more expensive. However an increasing number of marine  fish are being commercially bred leading to lower prices for fishkeepers.

Seawater

In order to look after marine fish the  first thing we need is the correct water. Seawater is a very complex cocktail  of many dissolved substances, and there are several varieties of synthetic  seasalts available from your local aquatic shop, that can be added to water to  make seawater. Making the correct strength of seawater is vital, and continually  monitoring the salt strength is also essential. Changes in salt concentration  will occur, most commonly due to evaporation.

Regular partial water changes are  essential and whenever one is performed, which may need to be done every week  in some tanks holding marine invertebrates,a new batch of seawater will need to  be made up to replace that taken out.

What  are the options?

There are many types of marine  aquarium, some contain only fish, others may house a mixture of fish and  invertebrates. A good ‘starter’ marine tank would hold hardy species such as  Moray Eels or ‘Volitans’ lionfish. These fish are a little more forgiving if  the water quality becomes slightly less than perfect. However both are  carnivores, moray eels can deliver a nasty bite and lionfish a dangerous sting.

There are many other  species of fish available for a fish only marine aquarium. Speak to your local  aquarium store for details .The usual rules of fishkeeping apply of not keeping  predators with smaller tank mates and expect aggressive behaviour from many  marine aquarium fish including species of Triggerfish and Tangs. Even tiny  damselfish can be very aggressive if a much larger fish strays into their  territory.

A fish only aquarium is a great way to  begin marine fishkeeping with different fish available to suit smaller tanks to  a huge aquaria.
There are many types of  invertebrate available for the marine aquarium. There is a staggering diversity  of corals and anemones, starfish and sea urchins, tubeworms and ‘feather  dusters’ shrimps and crabs.

All of them are simply beautiful  creatures but are very demanding to look after. They are intolerant of poor  water quality and often have very specific feeding and in some cases lighting  requirements.

Perhaps the pinnacle of  the marine aquarium world is the mixed fish and invertebrate aquarium often  called a ‘reef’ aquarium.The challenge here is finding the correct balance  between invertebrates and fish numbers and species.

But beware – many species of fish  regard the invertebrates that were carefully selected and lovingly cared for,  as a tasty meal. Whether you opt for fish only, inverts only or a mixed system,  always read up on your chosen animals and plan carefully to avoid problems with  aggression or predation. Remember small fish may become huge tank busters, and  small fish can have large territories

Basic  equipment

There is a massive array of equipment  available to run a marine aquarium, with reef tanks having vast banks of  equipment needed to maintain good water quality. For a simple marine aquarium  there are a few essential pieces of equipment:

Always aim to get the largest tank you  can. The greater the body of water in the tank the more stable the water  quality. Also you can then accommodate more livestock. The minimum tank size  for a marine aquarium is 100 L, anything less cannot provide stable water  quality.
A filter is an  essential piece of equipment as this processes the waste from the fish and  keeps the water healthy and clear. Fish only systems have more basic filtration  needs whereas ‘reef’ aquaria need very complicated external filters or  ‘live-rock’ filtration. Speak to your local aquatic store for advice. Make sure  you get a filter suitable for your tank, as this is the life-support system for  your fish and invertebrates.

Most marine aquaria have a protein  skimmer installed. This very useful piece of kit uses minute air bubbles to  strip fish wastes out of the water and helps the filter to keep the water  healthy and clear. There are many types available and they are an incredibly  useful addition to the vast majority of marine aquaria.
Fish only systems need  lighting sufficient to illuminate the tank and see the fish. Very bright lights  may make some fish timid, ‘Moon – lights’ are available which simulate night  time allowing you to watch nocturnal activities of your marine tank.

Reef aquaria have very specific  lighting needs.This is due to many corals, anemones, clams and others, having  minute algae in their tissues that they need to feed and grow. The algae is a  plant and thus needs light to photosynthesize food. Speak to your local aquatic  shop staff for more details on lighting requirements of your livestock.

Looking  after marine fish

Before starting your marine aquarium it  is essential to research the feeding requirements and behaviour of your planned  livestock. There are some essential questions to ask:

Will a fish eat its tank mates or  invertebrates?

Example  – Lionfish and frogfish can consume tank mates only slightly smaller than  themselves! Many butterfly fish will eat the invertebrates in a reef tank.

Can you  provide the food your livestock needs, remember some marine fish have very  specific feeding needs?

Example – many marine Angels and Butterfly fish have very specific feeding needs  which the average aquarist can not supply.

Can the fish compete for food in the  tank?

Example – seahorses  are poor swimmers and are rarely fast enough to get to food when kept with  other fish

How big  does the fish grow?

Example – A twin spot wrasse grows from a small spotted fish of 5 – 8 cm (2 – 3 inches)  into a monster that outgrows most home aquaria.

Is the fish aggressive?

Example – triggerfish are renowned  for their aggressive behaviour Stocking densities of marine fish are lower than  for freshwater aquaria.A marine tank can hold 20 – 30 cm body length (excluding  tail) of slender bodied fish per 100 L of water. For deeper bodied fish that  figure may drop to 10 cm of body length (excluding tail).

Looking  after marine fish

Once the aquarium is established its  day to day maintenance is similar to a freshwater aquarium. Herbivorous marine  fish may need feeding 2-3 times a day, or seahorse aquaria may need a regular  supply of live food , carnivores may be fed around twice a week. The most  important piece of maintenance on any aquarium is a regular partial water  change. In marine aquaria is especially imperative as the livestock is so  intolerant of poor water quality. A water change of 10 –20 % total volume  should be performed for invertebrate systems. For fish only systems 10 – 20%  fortnightly is reasonable. Regular testing of the water quality is also  essential as the water can become unhealthy very quickly if new fish are added,  too much food is added or a piece of equipment like a pump stops running. When  exposed to poor water quality the fish becomes stressed making them more  vulnerable to dangerous diseases.

When looking after a  marine aquarium it is essential to test the following water quality values each  week:

Specific gravity (Salt concentration) Ideal value = 35  grams of seasalt per litre
pH ideal value 8.1 – 8.3
Temperature 24 – 28 °C
Ammonia Ideal value = zero
Nitrite Ideal value = zero
Nitrate Ideal value = zero for aquaria housing invertebrates for fish only aquaria a maximum reading of 50 mg / L

Marine fishkeeping history

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

The Aztec Empire had 10 ponds of saltwater aquariums at Texcoco.^[2]

During the early days of marine aquaria, saltwater was collected at local beaches. Natural saltwater contains many unwanted organisms and pollutants. Aquarium literature of the time suggests that the most commonly kept marine fish were the percula clownfish, sergeant major damselfish, small, brackish-water pufferfish and scats, jeweled blennies, 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).

An ever-growing number of hobbyists experiencing the inconvenience of gathering natural sea water and the concurrent development of analytical chemistry techniques led to research into the chemical composition of sea water. Synthetic salt mixes were developed to replicate the chemical environment of the tropical ocean, including trace elements and salts. This advance made marine fishkeeping popular in areas without access to clean sea water.

Air driven, counter-current protein skimmers and reliable submersible electric heaters were invented in Germany. Various advances in filtration included trickle and hang-on filters, both allowing a more natural equilibrium in the aquarium environment. The advancement of fluorescent lighting technologies to provide higher output, along with metal halide lighting, enabled the first reef tanks, making it possible to keep corals and other invertebrates without natural sunlight.

More efficient chemical testing allowed aquarists to understand the chemical properties of aquariums. By the 1980s, a biologically-based understanding of how to maintain an artificial ocean environment brought more successful and widespread marine fishkeeping.

[edit] Modern fishkeeping

[edit] Marine aquarium components

The major components are an aquarium, usually made from glass or acrylic, filtration equipment, lighting, and an aquarium heater. Marine aquariums can range in volume from less than 80 litres, (< 20 US gal) to over 1,200 litres (300 US gal). Small volumes are more difficult to maintain due to the more rapid changes in water chemistry. The majority of saltwater aquariums are between 160 and 400 litres (40 and 100 US gal).

Nano reef aquarium maintained at home

[edit] Types of marine aquariums

Marine aquarists typically divide saltwater aquariums into those housing fish only, those housing fish with live rock, and those primarily designed to house corals and other invertebrates (also known as reef aquariums). Many fish hobbyists also divide the types of saltwater tanks based on the water temperatures at which they are kept.

[edit] Tropical marine

The most common type of saltwater fish tank, the tropical marine tank, houses marine animals from tropical climates. Usually kept between 24 to 28 °C (75 to 82 °F), these tanks include tropical reef tanks, as well as fish-only tanks. These tanks tend to have a low concentrations of microscopic plankton and other foods eaten by filter feeders. Most livestock for these aquariums are acquired through commercial means.

[edit] Temperate marine (coldwater marine)

A temperate marine aquarium

One of the more obscure types of fish tanks, the coldwater marine tank, holds fish of temperate climates, with temperatures ranging around 10 to 24 degrees Celsius (50–75 °F). While most of these tanks are not as aesthetically pleasing as their tropical counterparts, colorful species such as dahlia anemones and the ornate cowfish can be found. However most coldwater fish are gray or dull in color. Most colorful species are found in the western pacific. These tanks also tend to require extra skill to maintain.

Since coldwater cnidaria are rare and coldwater corals only occur at great depths, hobbyists are largely confined to fish, crustaceans and mollusks. Since there are very few commercially available coldwater fish, hobbyists usually have to physically acquire specimens. The most common way of doing this is by trolling or seining. Unlike commercially available tropical fish, whose behavior patterns and tank compatibilities are well documented, coldwater fish require much local ichthyology knowledge in order to maintain them.

Many temperate fish have specific local diet requirements, while others, like tautog (blackfish), will eat just about any crustacean or frozen foods. The blackfish should not be kept with crabs and mollusks, while other fish, like the oyster cracker toadfish, will do fine with any fish that is not small enough to fit into its mouth. Due to it being such a localized hobby, not many people go the route of local tanks. However, they are more cost-effective than reef tanks, cheaper and easier to maintain, and the fish hardier. It takes experience before one can successfully gage the compatibility of the fish in one’s area.^{[citation needed]}

[edit] 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 crabs, snails, feather dusters, brittle stars, starfish, limpets, abalones, and an occasional sea urchin, sea anemone, coral, and sea sponge. Also, if the aquarist is unlucky, a mantis shrimp. Bristleworms are also common, 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 to maintain high pH (8.0-8.3), alkalinity, and acid-neutralizing capacity. Alkalinity is often known by a rather confusing term, “carbonate hardness“, or KH. This is usually measured in “degrees” (dKH) or meq/L.

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. Live rock usually arrives from online dealers as “uncured”, and must be quarantined in a separate tank while undergoing the curing process, which involves the inevitable die-off of some of the rock’s inhabitants and the subsequent production of undesirable ammonia and nitrite. 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.

Sometimes hobbyists use so-called “dead rock”, which is simply old live rock that has been allowed to dry out and to lose most of its live inhabitants, to keep unwanted pests out of their aquariums, and as an inexpensive alternative to live rock.

[edit] Filtration

A new sump with three compartments including a protein skimmer

In general, marine aquariums have more complex filtration requirements than most freshwater aquariums. The various components frequently include wet and dry filters and protein skimmers. Protein skimmers are devices that remove organic compounds prior to their degradation, and are very useful in marine aquariums. Protein skimming is also used in the popular Berlin method that relies on live rock and periodic partial water changes to degrade and remove waste products. The Berlin method requires large amounts of live rock in the aquarium. The rule of thumb is 1/2–1 lb. per 1 US gallon (0.2–0.4 kg per 4 liters).

Some marine aquariums include a sump, which is an external container connected to the main aquarium with a water pump. In most setups, the sump is located below the aquarium and is fed water from the main tank via an overflow. An overflow at its simplest is a round hole drilled towards the top of the tank, connected via tubing to an output below it. As the water level increases past the height of the overflow, the water “overflows” the tank and falls through to the sump below. The water circulation is powered by a water pump in the sump, which pushes the water back into the tank, thus causing more water to flow over and perpetuating the cycle. There are many advantages to using a sump, both for the appearance and the health of the tank. The sump helps the appearance of the tank, because it allows filtration and maintenance equipment (protein skimmer, heater, activated carbon) to be kept out of sight of the main tank. It also ensures that the water level of the main aquarium never changes, as the overflow sets the water level in the main tank. The sump aids tank health by helping to oxygenate the water by increasing the amount of water/air surface area used for gas exchange.

Some marine aquariums also include a refugium. Refugiums are small containers or aquariums that are hidden behind or beneath the main aquarium and connected to it via a water pump (often in a similar manner to a sump). Refugiums have recently become quite popular among reef aquarists because they can be used to serve several purposes such as adding water volume or providing a fish-free site for biological filtration in live rock and/or the sandbed. Fish-free refugiums host populations of copepods, amphipods, isopods, and other zooplankton.

[edit] Lighting

A DIY metal halide pendant lamp

Regular cyclical lighting is used in aquariums to simulate day and night. This is beneficial for fish and invertebrates since it establishes a routine, enables them to rest, and makes them feel more secure. Aside from establishing a routine, high output lighting is required for many invertebrates such as corals and anemones to survive. Lighting in marine tanks that contain only fish and live rock is not an important issue. In aquariums containing invertebrates, however, where algal growth (of both free-living and symbiotic algae) is desired, more intense lighting is required. Various light sources include but are not limited to: natural sunlight, fluorescent, VHO fluorescent (Very High Output), T-5 fluorescent, compact fluorescent, LED and metal halide. Each type of lighting has its own advantages and disadvantages. They all vary in initial cost, maintenance cost, spectrum obtainable, longevity, efficiency, and power.

[edit] Natural sunlight

The most primitive lighting source is natural sunlight. This is only effective in areas near the equator because the intensity of sunlight is greatest there. Efficiently utilizing natural sunlight requires complex planning and, as such, this method is applied on only the largest reef systems. Many times in the hobby natural sunlight is actually avoided due to the low spectrum of lighting it has. The yellow tint is often undesirable and can encourage bad algae growth.

[edit] Incandescent

Incandescent lamps have been phased out over the years. They are wasteful of energy, producing between 15 and 30 lumens per watt of power (out of a possible 683 lumens per watt for an ideal light source). They can be found many times in older aquarium light hoods. They burn out frequently, put off a lot of heat, and normally do not have an appropriate spectrum associated with them. Most incandescent lamps can be replaced with commonly available and efficient screw in power compact bulbs.

[edit] Standard fluorescent

Standard fluorescent tubes are the common light bars you find in commercial ceilings. Fluorescent lighting has more color temperatures available which are more suited to aquariums than those of incandescent bulbs. They are also more efficient than incandescent lighting, averaging between 90 and 95 lumens per watt. The downside to regular fluorescent lights is that they do not have the intensity to penetrate into deeper aquariums.

[edit] Higher output fluorescent

There are several improved variations of fluorescent technology. The main ones are very high output (VHO), power compact fluorescent (PC), and T-5 high output (HO).

VHO fluorescent lamps run at higher power levels, usually about three times the standard wattage for a given bulb length. They have the advantage of high light output, but the larger diameter bulbs limit the efficiency of reflectors and the number of bulbs that can be fit in an aquarium hood.

PC lighting is also high-power fluorescent lighting, but the tubes are thinner and are often folded over one another to reduce size. Most spiral shaped energy efficient light bulbs commercially available for house lighting are power compact fluorescent bulbs. PC bulbs are recommended to be replaced every six months to a year to keep the desired light spectrum.

T-5 HO lights are the newest variation on fluorescent lights. They are run at slightly higher power levels than standard fluorescent lamps, but are made significantly thinner than standard fluorescent bulb. This allows for more efficient reflector designs that get more light into the aquarium. Higher quality T-5 systems often match or exceed the output of equivalent power compact fluorescent or VHO lighting fixtures. On the downside, T-5 lighting is the most expensive type fluorescent lighting available. Many times it is much cheaper per watt, especially in the long run with the multiple T-5 bulbs being replaced, to go with an equivalent metal halide light setup over a T-5 setup if such high light output is requried.

All types of fluorescent lighting offer the same efficiency in lumens per watt; it is the shape of the bulb and reflectors that makes their overall outputs different.

[edit] Metal halide

Metal halide lights are generally the highest output lighting commercially available. They produce about 90-100 lumens per watt of power. This is roughly the same as fluorescent. The improvement with metal halides is that they concentrate this light output into a very small space, whereas fluorescent lights evenly illuminate the entire aquarium. This is often referred to as point source lighting, and is what causes the rippling visual effect on many advanced aquarium setups. This concentration of light output increases the intensity, allowing metal halide lamps to penetrate light to even the very bottom levels of most aquariums. Metal halides are available in many color temperatures, from 6500 K up to 20,000 K, though bulbs as high as 50,000 K are occasionally found. The downsides of metal halide lighting are the initial cost and the heat produced.

Most metal halide fixtures are more expensive than fluorescent systems, but are required for some reef setups. Halide lamps concentrate heat as well as light output. The surface of an operating lamp becomes hot enough to cause second or third degree burns instantly, so this lighting technology must be used with caution. The heat produced can also warm the aquarium to unacceptable levels, possibly necessitating the use of a chiller for certain aquarium setups.

[edit] LED

The most recent addition to the list of aquarium lighting technologies is LED lighting. These have the potential to be much more efficient than any other technology, but are not fully developed. LEDs have the advantage of point source lighting, but are also adjustable to most power levels. This allows for more advanced lighting schedules, the simulation of cloud cover, or even lightning storms. So far, LEDs have found use mainly as lunar lighting in commercial products.

Reef-keeping enthusiasts have began to build their own LED light fixtures as well. Debate over their effectiveness towards coral is still inconclusive, particularly with respect to their ability to give off UV radiation, critical to obtaining a vibrant array of colors that most people interested in LED lighting are looking for.^[3]

LED lighting can be considered one of the most energy efficient and low impact options to lighting a reef tank as well, with a projected life expectancy of seven years.

[edit] Overall lighting considerations

When considering lighting for an aquarium, there are generally two factors to consider: wattage and color temperature. Depending on the type of lighting (i.e. fluorescents, metal halide, etc.) the wattage of light emitted may vary considerably, from tens of watts to several hundred watts in a lighting system. Wattage, while not indicative of color, is equivalent to power and essentially determines how brightly the light will shine. Due to the scattering of light in water, the deeper one’s tank is, the more powerful the lighting required. Color temperature, measured in kelvins (albeit slightly unrepresentively) refers to the color of light being emitted by the lamp and is based on the concept of blackbody radiation. Light from the sun has a color temperature of approximately 5900 K and lighting systems with color temperatures >5000 K tend to be best for growing plants in both the marine and freshwater setting. 10,000 K light appears bluish-white and emphasizes coloration in fishes and corals. Higher up on the spectrum there are 14,000 K and 20,000 K bulbs that produce a deep blue tint which mimic the lighting conditions underseas, creating an optimal ambience for invertebrates and livestock present.

[edit] Heating

Most marine aquarium inhabitants are endemic to tropical reefs and waters in Africa, Southeast Asia, and the Red Sea. Marine aquarium temperatures should mimic the natural environment of the inhabitants and are most commonly maintained at 23 to 28 degrees Celsius (73-82 °F). In regions where the ambient temperature is less than the desired temperature of the aquarium this generally necessitates the use of an aquarium heater. In some areas ambient temperature is greater than the desired temperature and refrigeration devices, known as “chillers”, are used to cool the aquarium water.

[edit] Water testing

Marine aquarists commonly test the water in the aquarium for a variety of chemical indicators of water quality. These include:

• Specific gravity, a relative measure of water density, is normally maintained between 1.020 and 1.024 in aquariums with fish only, and 1.023 and 1.026 for aquariums containing invertebrates.^[4]
• Salinity should therefore be between 28 and 35 ppt, with the higher values being beneficial in advanced reef systems.^[4] Because salinity is by definition directly related to specific gravity, both can be tested with an inexpensive hydrometer or refractometer.
• pH should be maintained between 8.1 and 8.3.
• Ammonia should be near zero.
• Nitrite should be near zero.
• Nitrate should be well below 10 ppm, but close to zero is best.
• Phosphate should be below 0.3 ppm.
• Alkalinity should be 3.2–4.5 meq/L. or 7 and 12 degrees of carbonate hardness (dKH). ^[5][4]
• Copper concentration should be measured and not rise over 0.15 ppm^[6]

pH can be raised with a commercially available buffering agent or through calcium-rich substrates. A calibrated calcium reactor can assist in maintaining both pH and alkalinity. Using purified water from a reverse osmosis/deionization (RO/DI) unit can prevent KH and pH fluctuation.

The nitrogen cycle refers to the conversion of toxic ammonia to nitrite and finally nitrate. While fish waste (urine and feces) and decaying matter release ammonia, the majority of ammonia released (approximately 60%) in both marine and freshwater aquariums is excreted directly into the water from the 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 is converted via an anaerobic bacterial process to free nitrogen, but this process is very difficult to maintain. In the recent past, most nitrate, which is less toxic to fishes and most invertebrates than nitrites, accumulated in the water until it was physically removed by a water change. However, many marine aquarists are now employing the use of a special section of the tank or separate tank altogether, called a “refugium.” A refugium is, as its name suggests, a sheltered area that shares water with the primary, or display, tank. Refugiums usually contain a deep sand bed to allow anoxic zones to develop within them where anaerobic bacteria can convert nitrate into nitrogen gas, a useful means of nitrate removal. Various types of macroalgae can be grown and harvested from the refugium as another means of nitrate export. As refugiums become more common in marine aquaria, nitrate levels are easily manageable for even the novice hobbyist. Ammonia and nitrite should be tested regularly; any detectable levels (i.e., over 0 ppm) can be indicative of a problem. Nitrates should not exceed 2 ppm in reef tanks, or 20 ppm in fish-only tanks. It is sometimes acceptable to have a small amount of nitrate buildup, as some livestock, especially fish, are fairly tolerant of nitrate. Most corals, while able to assimilate nitrate, cannot be expected to survive, much less thrive, with high nitrate concentrations.

Other suggested tests include those for calcium, carbonate alkalinity, magnesium, and other trace elements. It is often beneficial (and necessary) for the aquarist to research the water chemistry parameters for the specific organism that is desired.

[edit] Acclimation

Acclimation is a process that is performed when adding new marine life to an aquarium, particularly for invertebrates, who lack osmoregulation. This process slowly introduces the organisms to the water composition of the new environment, preventing shock resulting from sudden changes in water chemistry. There are several different methods of doing this, including the use of a drip line, or of a measuring cup or other device to slowly mix water from the aquarium tank into a container with the new animal.

The drip line or trickle acclimating method is a safe and gentle way to introduce saltwater fish into a new home, and is a fairly simple one to perform. This procedure can be used to acclimate all types of marine as well as freshwater livestock. First, the fish is placed with all the bag water in a bucket or container of sufficient size for the fish to be reasonably covered with the water, and the bucket is then set on the floor next to the aquarium. Using some plastic air line tubing and an air gang valve, a siphon drip line is set up from the aquarium to the bucket. Tank water is allowed to drip slowly into the bucket, using the gang valve to adjust the drip rate, until the water dripped into the bucket equals about two to three times the original volume of the bag water. After testing the pH, salinity, and temperature of the water in the bucket to see if these parameters match that of the tank water, the fish is gently removed and placed into the tank.^[7]

[edit] Water changes

Water changes are a staple of good saltwater maintenance. Larger (approximately 200 gallon) aquariums are much more stable and water changes may not need to take place if the nitrogen cycle has fully established itself in the tank, although this is a controversial statement among aquarists. Water changes are used to maintain balance of calcium, carbonate alkalinity, and magnesium which are rapidly depleted in a reef aquarium, while also maintaining levels of other trace elements as well as removing toxic solutes which may accumulate from many different sources and are unable to be removed by even advanced filtration methods. Supplements are needed (such as calcium) when regular water changes alone are not able to maintain adequate levels, particularly those of calcium, carbonate, and magnesium. Water changes involve removing a fraction of the total volume of the aquarium, replacing that water with new pre-mixed saltwater. Pre-mixed saltwater has been dechlorinated and/or dechloraminated—typically with an additive such as bisulfite or through filtering. Water should be brought to the same temperature if more than a 5% change is occurring. Salinity should match that of the aquarium, or be dosed very slowly if altering the salinity. Aging and aerating saltwater (such as in a bucket with a powerhead or airstone) is recommended as good practice to allow the pH to stabilize.

Replacement water should be of the same source as the aquarium, whether it be reverse osmosis (RO), de-ionized (DI), distilled or from a municipal supply, in order to avoid drastic changes in water chemistry. In cases where one is replacing a tap water-based salt mix with a reverse osmosis-based salt mix, the replacement water should be added slowly over the course of several hours to avoid sending the aquarium inhabitants into osmotic shock. However, large water changes are not advised under routine circumstances anyway, so this is really irrelevant. Municipal, or tap water, is not recommended for a marine aquarium as it often contains high levels of nitrates, phosphates, and silicates and other dissolved solids which fuel the growth of nuisance algaes, particularly diatoms, which appears as a rust colored powdery algae and grows in the overabundance of silicates present in all tap water. Water filtered by a four stage process including mechanical, carbon, reverse-osmosis, and de-ionizing components is recommended as this can provide the easiest route to absolutely pure water. Four and Five stage RO/DI filtration units can be obtained for as little as $100 and are a cost effective means of converting tap water into water usable in a marine aquarium.

[edit] Conservation

Almost all species kept in marine aquaria at this time are caught in the wild, although tank-raised specimens are becoming increasingly common as a viable alternative. Only a few species such as clownfish are captive-bred on a commercial scale. Much collecting is done in Indonesia and the Philippines, where use of cyanide and other destructive collection methods, while discouraged, is unfortunately common. The majority of live rock is also harvested in the wild, and recent restrictions on this harvest in Florida have caused a shift to Fijian and aquacultured rock. Natural rock, because it is created by coral polyps, takes many years if not centuries to form, and is a vital habitat for countless marine species; thus, commercial-scale harvesting of naturally-occurring live rock has been criticized by conservationists. Additionally, many animal species sold to hobbyists have very specific dietary and habitat requirements that cannot be met by hobbyists (e.g. Labroides genus wrasses, the moorish idol); these animals almost inevitably die quickly and have markedly reduced lifespans compared to wild specimens. Often these specific environmental requirements cause improperly housed lifestock’s color and appearance to be poor. These issues are often downplayed by individuals and organizations with a financial interest in the trade. Hobbyists who support conservation should buy only certified net-caught fish (although ensuring the legitimacy of such claims can be difficult) or captive-raised fish, as well as farmed corals and to support legitimate reef conservation efforts. The majority of corals can be “fragged”, whereby a portion of a larger captive coral is separated and can subsequently be raised into an individual specimen, allowing for coral propagation within the domestic aquarium; the trade in frags (i.e. fragments) offers a fantastic opportunity for marine aquarists to obtain new and unique corals while limiting the impact on the natural environment. Rare species and those without a history of being successfully kept in captivity should be avoided.

[edit] Commercial development

Various businesses have commercialized fishkeeping. With the advent of large scale business operations focusing on breeding massive quantities of specimens, marine fishkeeping has become much more widespread than ever before. Perhaps the biggest disincentive to marine fishkeeping, in comparison to freshwater, is the initial setup cost. A 100 US gallon (400 L) reef tank full of coral and equipment can cost in excess of $2,500 US, although a budget-minded home hobbyist could spend less than half of this and still get a satisfactory