Marine aquarium
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.
The first saltwater tanks were Venetian glass jars where the Romans kept anemones outdoors, but these systems were very short lived.
[2] In 1846, Anna Thynne maintained stony corals and seaweed for almost three years, and was credited as the creator of the first balanced marine aquarium in London.
[3][4] Personal saltwater fishkeeping began on a wider scale in the 1950s, starting with the basic rectangular glass aquariums (usually 20 gallon), still popular today.
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.
By the 1980s, a biologically-based understanding of how to maintain an artificial ocean environment brought more successful and widespread marine fishkeeping.
Since coldwater coral reefs only occur at great depths, most hobbyists are largely confined to fish, sea anemones, crustaceans, echinoderms, mollusks and Feather duster worms.
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 sump aids tank health by helping to oxygenate the water by increasing the amount of water/air surface area used for gas exchange.
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.
In marine aquariums containing corals, or other photosynthetic invertebrates, where algal growth (of both free-living and symbiotic algae) is desired, more intense lighting is required.
Efficiently utilizing natural sunlight requires complex planning and, as such, this method is applied on only the largest reef systems.
VHO fluorescent lamps run at higher power levels, usually about three times the standard wattage for a given bulb length.
Higher quality T-5 systems often match or exceed the output of equivalent power compact fluorescent or VHO lighting fixtures.
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.
This is often referred to as point source lighting, and is what causes the rippling visual effect on many advanced aquarium setups.
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.
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.
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.
Most marine aquarium inhabitants are endemic to tropical reefs and waters in Africa, Southeast Asia, and the Red Sea.
As refugiums become more common in marine aquaria, nitrate levels are easily manageable for even the novice hobbyist.
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.
Larger (approximately 200 US gallons (760 L)) 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 cannot be removed by even advanced filtration methods.
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.
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 appear as a rust-colored powdery algae and grows in the overabundance of silicates present in all tap water.
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.
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.
A 100 US gallons (380 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 result.
