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\".
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 that already has live rock. Live rock harbors a wide variety of corals, algae, sponges, and other invertebrates, when they are collected. Corals added to the aquarium later will often become attached to the rock.
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 that hosts aerobic and anaerobic nitrifying bacteria required for the nitrogen cycle that processes waste. 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.
The use of live rock immediately introduces into the aquarium numerous algae, bacteria and small invertebrates all of which contribute to the overall quality of the aquarium water. Live rock has just as much, if not more, surface area for bacteria than a trickle filter. Since live rock in the aquarium contains various types of bacteria, algae and corals, waste products such as ammonia, nitrate and phosphate can have a number of fates. Ammonia, nitrate and phosphate are readily assimilated by algae and photosynthetic corals growing on and in the rock. Ammonia can also be quickly converted into nitrate by the bacteria on and in the rock. This nitrate can be either absorbed by the algae and corals, or it can be denitrified by bacteria in close proximity to the nitrate-producing bacteria.\"
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.
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, Tonga, and the Marshall Islands, as well as from 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, or dry rock, is a generic term for aragonite rock that has no organisms growing in or on the rock. 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 from combining crushed aragonite, sand, and Portland cement. 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.
As of August 4, 2008 CITES (Convention on International Trade in Endangered Species) banned the collection of live rock from Tonga, the Marshall Islands, and the Cook Islands. This is due to the over-collecting of rock in these areas. This ban remains in effect as of 2022.
Hey everyone, lately I've been a bit critical of the surface appearance of my live rock and I'm unsure as to whether my expectations are unrealistic or if my my live rock is just plain dirty. I've included a few pictures in the details segment but in short I just can't seem to get rid of the brown discolored portions of my live rock. Is it supposed to look like this if not, what steps can i do to clean it up or help the coraline algae cover more area.
I haven't been in the hobby very long but I've come to find that good reef lighting or actinics can really hide a lot of the uglier yellow-brown coloration of rock or even the algae that clings to it. My water parameters are good and have been verified by my lfs. I've tried to manually clean the rock with a toothbrush and increase water flow on it but I can't seem to get anymore results.
It seems like the coraline algae is constantly at war along many fronts with the discolored / bare rock. Are these areas where the coraline just doesn't grow due to lighting or something I would like to think that with a solid long term maintenance regime and pristine water conditions my live rock will eventually be completely encrusted in coraline algae but I've seemed to have reached a \"plateau\" in the improvement. Perhaps this is just the natural mature state of live rock It would be great to see what your guys' live rock looks like under normal room lighting.
Here's what old live rock can look like, but mind you that these rocks were around 11 years old when I took this picture (they spent over 9 years in a high nutrient, unfiltered 55g tank before being used in this nano):
I had really awesome purple rocks in my tank until I decided to get high light sps. I upped the lighting and the coralline disappeared. It was very sad. Keep calcium, alk, magnesium high, keep light low, and flow high. You can try to speed things up by sprinkling bare areas with coralline scrapings from elsewhere.
So if I maintain a good flow, suspended nutrients (will this come just from feeding my fish), low-medium light, adequate calcium, alkalinity and magnesium it will just be a matter of patience And will coraline algae be inhibited at all by the other stuff covering my rock My water parameters are as follows...
My current 7 year old nano, by contrast, is maintained more diligently. It grows almost no coraline algae growth on the tank walls and equipment, but has at least maintained much of the thicker growth that the live rock had initially from the 55g. The conditions for this nano are quite different (higher intensity LED lighting, weekly 10% WCs, regular detritus removal, untestable P04 (Salifert), low NO3 at 0.5ppm, pH 8.4, alk 9.0 dKh, Ca 420 ppm, Mag 1250 ppm.
I really appreciate your responses. My understanding now is with a bit of ongoing parameter investigation and patience I should be able to obtain picture perfect live rock. Onto my second question, if you look at the third photo of mine - just below and above the candy coral there are white patches which used to be purple coraline growth. It happened quite rapidly and overall I lost probably 40% of my coraline growth in about 3 days. I suspect a bit of GFO overdose as the culprit but maybe some others have had similar experiences 59ce067264