Live rock is rock from the

ocean The ocean (also the sea or the world ocean) is the body of salt water that covers approximately 70.8% of the surface of Earth and contains 97% of Earth's water. An ocean can also refer to any of the large bodies of water into which the wor ...

that has been introduced into a saltwater aquarium. Along with

live sand Live sand, a term used in aquarism, is natural reef coral sand populated with millions of beneficial bacteria and organisms which aid in the dissolving of organic wastes like ammonia, nitrites and nitrates produced by larger organisms in saltw ...

, it confers to the closed marine system multiple benefits desired by the saltwater

aquarium An aquarium (plural: ''aquariums'' or ''aquaria'') 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, aq ...

hobbyist A hobby is considered to be a regular activity that is done for enjoyment, typically during one's leisure time. Hobbies include collecting themed items and objects, engaging in creative and artistic pursuits, playing sports, or pursuing oth ...

. The name sometimes leads to misunderstandings, as the "live rock" itself is not actually alive, but rather is simply made from the

aragonite Aragonite is a carbonate mineral, one of the three most common naturally occurring crystal forms of calcium carbonate, (the other forms being the minerals calcite and vaterite). It is formed by biological and physical processes, including pre ...

skeletons of long dead

coral Corals are marine invertebrates within the class Anthozoa of the phylum Cnidaria. They typically form compact colonies of many identical individual polyps. Coral species include the important reef builders that inhabit tropical oceans and se ...

s, or other calcareous organisms, which in the ocean form the majority of

coral reefs A coral reef is an underwater ecosystem characterized by reef-building corals. Reefs are formed of colonies of coral polyps held together by calcium carbonate. Most coral reefs are built from stony corals, whose polyps cluster in groups. ...

. When taken from the ocean it is usually encrusted with

coralline algae Coralline algae are red algae in the order Corallinales. They are characterized by a thallus that is hard because of calcareous deposits contained within the cell walls. The colors of these algae are most typically pink, or some other shade of re ...

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".

Origin

Live rock is harvested for use in the aquarium from reefs, either from natural or human breakage. It may also be "seeded" from small coralline rocks by an aquaculturalist in warm ocean water, to be harvested later. Live rock can also be seeded by adding base rock to an active

reef aquarium A reef aquarium or reef tank is a marine aquarium that prominently displays live corals and other marine invertebrates as well as fish that play a role in maintaining the tropical coral reef environment. A reef aquarium requires appropriatel ...

that already has live rock. Live rock harbors a wide variety of corals,

algae Algae (; singular alga ) is an informal term for a large and diverse group of photosynthetic eukaryotic organisms. It is a polyphyletic grouping that includes species from multiple distinct clades. Included organisms range from unicellular micr ...

sponges Sponges, the members of the phylum Porifera (; meaning 'pore bearer'), are a basal animal clade as a sister of the diploblasts. They are multicellular organisms that have bodies full of pores and channels allowing water to circulate through t ...

, and other

invertebrates Invertebrates are a paraphyletic group of animals that neither possess nor develop a vertebral column (commonly known as a ''backbone'' or ''spine''), derived from the notochord. This is a grouping including all animals apart from the chordat ...

, when they are collected. Corals added to the aquarium later will often become attached to the rock.

Purpose

Live rock is highly valued in the aquarium trade. It introduces a diverse array of bacteria, algae, and invertebrates to the closed marine environment and functions as a superior

biological filter A trickling filter is a type of wastewater treatment system. It consists of a fixed bed of rocks, coke, gravel, slag, polyurethane foam, sphagnum peat moss, ceramic, or plastic media over which sewage or other wastewater flows downward and ...

that hosts aerobic and anaerobic nitrifying

bacteria Bacteria (; singular: bacterium) are ubiquitous, mostly free-living organisms often consisting of one biological cell. They constitute a large domain of prokaryotic microorganisms. Typically a few micrometres in length, bacteria were am ...

required for the

nitrogen cycle 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 biolo ...

that processes

waste Waste (or wastes) are unwanted or unusable materials. Waste is any substance discarded after primary use, or is worthless, defective and of no use. A by-product, by contrast is a joint product of relatively minor economic value. A waste pr ...

. Live rock becomes the main biological nitrification base or biological filter of a saltwater aquarium. Harmful elements dissolved in the water of the aquarium, including ammonia, phosphates, and nitrates, are processed with the help of the organisms that are introduced from the live rock into the aquarium's ecosystem. Excess ammonia, nitrate, and phosphates are eliminated with the help of the algae and corals growing on the live rock's surface, while other bacteria supplement the process and restore balance in the water chemistry. Additionally, live rocks have a stabilizing effect on the water chemistry, in particular on helping to maintain constant pH by release of calcium carbonate. Lastly, live rock, especially when encrusted with multiple species of coralline algae (producing differing colors), becomes a major decorative element of the aquarium and provides shelter for the inhabitants. It is often used to build caves, arches, overhangs, or other structures in the tank, a practice known as

aquascaping Aquascaping is the craft of arranging aquatic plants, as well as rocks, stones, cavework, or driftwood, in an aesthetically pleasing manner within an aquarium—in effect, gardening under water. Aquascape designs include a number of distinct styl ...

In J. Charles Delbeek's article ''Your First Reef Aquarium'', he states, Live rock must however be cured prior to aquarium installation. Many of the organisms that previously lived in the rock would have died off during the harvesting and transportation process posing a risk to an immature aquarium of rapid ammonia production due to the dead organisms decomposing. To combat this a curing process must be carried out involving leaving the rock to sit in water for up to several weeks to ensure all dead organisms have decomposed and no longer pose a threat to water quality.

Types

There are many different types of live rock. Each is named after the area from which it originated. A large amount of live rock comes from the Southern Pacific region, in areas such as

Fiji Fiji ( , ,; fj, Viti, ; Fiji Hindi: फ़िजी, ''Fijī''), officially the Republic of Fiji, is an island country in Melanesia, part of Oceania in the South Pacific Ocean. It lies about north-northeast of New Zealand. Fiji consis ...

Tonga Tonga (, ; ), officially the Kingdom of Tonga ( to, Puleʻanga Fakatuʻi ʻo Tonga), is a Polynesian country and archipelago. The country has 171 islands – of which 45 are inhabited. Its total surface area is about , scattered over in ...

, and the

Marshall Islands The Marshall Islands ( mh, Ṃajeḷ), officially the Republic of the Marshall Islands ( mh, Aolepān Aorōkin Ṃajeḷ),'' () is an independent island country and microstate near the Equator in the Pacific Ocean, slightly west of the Inte ...

, as well as from the

Caribbean The Caribbean (, ) ( es, El Caribe; french: la Caraïbe; ht, Karayib; nl, De Caraïben) is a region of the Americas that consists of the Caribbean Sea, its islands (some surrounded by the Caribbean Sea and some bordering both the Caribbean ...

. Each has its own distinct qualities that make it preferable to certain reef aquarists. For instance, live rock from the Fiji region is often porous and large, and rock from the Tonga region is often dense and elongated.

Base rock

Base rock, or dry rock, is a generic term for aragonite rock that has no organisms growing in or on the rock.What is Live Rock
in

About.com Dotdash Meredith (formerly About.com) is an American digital media company based in New York City. The company publishes online articles and videos about various subjects across categories including health, home, food, finance, tech, beauty, ...

Base rock is often used as filler rock in the aquarium as it is much cheaper to purchase than live rock. In time, base rock will become colonized by living organisms. Recently base rock that is mined from inland ancient reefs has become a popular way to keep the aquarium trade going sustainably. This rock is either maricultured and sold as live rock, or can be purchased and grown in the home aquarium. Base rock can also be made from artificial rock called aragocrete, which is a hand made

concrete Concrete is a composite material composed of fine and coarse aggregate bonded together with a fluid cement (cement paste) that hardens (cures) over time. Concrete is the second-most-used substance in the world after water, and is the most wid ...

from combining crushed aragonite,

sand Sand is a granular material composed of finely divided mineral particles. Sand has various compositions but is defined by its grain size. Sand grains are smaller than gravel and coarser than silt. Sand can also refer to a textural class ...

, and

Portland cement Portland cement is the most common type of cement in general use around the world as a basic ingredient of concrete, mortar, stucco, and non-specialty grout. It was developed from other types of hydraulic lime in England in the early 19t ...

. After allowing the cement to dry, the pieces are sometimes acid washed to counteract the high pH of the materials, and then allowed to soak in clean water for one or more months. They generally tend to be heavier and less attractive when compared to natural base rock.

Collection ban

As of August 4, 2008

CITES CITES (shorter name for the Convention on International Trade in Endangered Species of Wild Fauna and Flora, also known as the Washington Convention) is a multilateral treaty to protect endangered plants and animals from the threats of intern ...

(Convention on International Trade in Endangered Species) banned the collection of live rock from

, the

, and the

Cook Islands ) , image_map = Cook Islands on the globe (small islands magnified) (Polynesia centered).svg , capital = Avarua , coordinates = , largest_city = Avarua , official_languages = , lan ...

. This is due to the over-collecting of rock in these areas. This ban remains in effect as of 2022.

References

External links

About Live Rock
and its purpose {{DEFAULTSORT:Live Rock Fishkeeping