What is Live Rock?: The Foundation of Your Reef Aquarium
Why is it Called Live Rock? Is it Really Alive?
Despite its name, live rock itself is not alive in the way that plants and animals are. The term “live rock” refers to the living organisms that inhabit the porous surface and internal structure of the rock, rather than the rock itself. This distinction is crucial for understanding both the role of live rock in an aquarium and the care it requires.
The Composition of Live Rock
Live rock originates from coral skeletons and calcium carbonate-based substrates that have broken off from existing coral reefs or similar oceanic structures. Over time, these rocks become colonised by a diverse array of marine life, including bacteria, algae, sponges, worms, crustaceans, and tiny invertebrates. This colonisation process is what transforms an inert piece of rock into a vibrant, living biological filter and ecological habitat.
The Living Surface
The surface and internal cavities of live rock are teeming with life, primarily beneficial bacteria. These bacteria are the powerhouse behind the nitrogen cycle in reef tanks. They convert harmful ammonia released by fish and other waste into nitrite, and then into less harmful nitrate, helping to maintain the water quality that is critical for the health of all tank inhabitants.
Microfauna and More
Beyond bacteria, live rock hosts a variety of microorganisms and small creatures, which are often too tiny to be seen without magnification but are vital to the tank’s biodiversity. These organisms can include copepods, amphipods, small worms, and various types of microalgae. They not only contribute to the biological diversity of the aquarium but also serve as a natural food source for many marine species, especially picky eaters like mandarin fish or coral beauties.
Is Every Rock a “Live Rock”?
It’s important to note that not all rocks placed in an aquarium become live rock. The transformation depends on the rock’s porosity, which allows for adequate water flow and surface area for colonisation, and the presence of live organisms to colonise it. Artificial live rock, for example, is designed to mimic these properties and can become live over time as it gets colonised by bacteria and other organisms from the water and other live rocks in the aquarium.
So, while the rock itself isn’t alive, the term “live rock” accurately describes the dynamic, living ecosystem that the rock supports within its structure. This ecosystem plays a critical role in the health and stability of reef aquariums, making live rock a foundational element not just structurally but also biologically. Understanding this helps aquarists appreciate the vital functions these rocks perform beyond their aesthetic value, ensuring they are properly cared for to maintain their beneficial properties.
Live rock is not just a staple in the reef aquarium hobby; it is the very foundation upon which successful reef ecosystems are built. Whether you’re a seasoned aquarist or just starting out, understanding what live rock is and its critical role in your reef tank is essential. This comprehensive guide will explore what live rock is, its benefits, how to select it, and best practices for incorporating it into your reef tank.
Understanding Live Rock
Live rock refers to the pieces of coral skeleton that have broken off from reefs and are collected for use in aquariums. But live rock is much more than just a rock. It is alive with a myriad of microscopic and macroscopic marine life. This includes bacteria, algae, crustaceans, and small invertebrates, all of which contribute to the ecological balance of a reef aquarium.
The Origin of Live Rock
Live rock typically comes from coral reefs in the ocean, where it serves as an essential component of the natural reef ecosystem. After being harvested, it is often cured to remove dead organisms and excess organic material, preparing it for safe introduction into an aquarium.
Types of Live Rock
• Natural Live Rock: Directly harvested from the ocean, this rock includes all the microorganisms that were living on it. It is often considered the most “authentic” form of live rock.
• Aquacultured Live Rock: Grown in controlled marine environments to reduce the impact on natural reefs. This type of rock is sustainable and often hosts a controlled, yet diverse, biological community.
• Artificial Live Rock: Man-made from various types of marine-friendly materials, designed to mimic the function of natural live rock without the environmental downsides of harvesting.
Benefits of Live Rock in a Reef Aquarium
Live rock is crucial for several reasons:
Biological Filtration
Live rock is the ultimate biological filter. The porous nature of live rock provides an ideal habitat for beneficial bacteria that process ammonia and nitrite into less harmful nitrate, a process known as the nitrogen cycle. This bacterial process is vital for maintaining water quality in a closed reef system.
Habitat and Shelter
Live rock provides structure, shelter, and territory for the various organisms within a reef aquarium. Fish, corals, and invertebrates use the crevices and caves of live rock for protection and spawning, which is crucial for their natural behaviour and wellbeing.
Aesthetic Value
Live rock can dramatically enhance the aesthetic appeal of an aquarium, offering a natural and rugged beauty that forms the perfect backdrop for colourful corals and fish. It allows aquarists to create intricate landscapes that mimic natural reef structures.
Choosing the Right Live Rock
When selecting live rock, consider the following:
• Source: Opt for sustainably sourced live rock, whether aquacultured or sustainably harvested, to minimize environmental impact.
• Porousness: Look for rocks that are lightweight and porous, as they provide more surface area for biological filtration and habitat.
• Appearance: Choose rocks that fit the visual goals of your aquarium, considering size, shape, and colour.
Best Practices for Using Live Rock
• Curing Live Rock: If you obtain natural live rock, it may need to be cured to remove dead organic matter. This involves placing the rock in a setup with heated saltwater, good circulation, and filtration, and allowing it to “cure” for several weeks.
• Arrangement: When placing live rock in your aquarium, aim for a stable structure that offers plenty of crevices and caves, ensuring good water flow throughout the structure.
• Maintenance: Regularly check and maintain your live rock for algae growth and detritus buildup. Careful scrubbing during water changes can help maintain its efficacy and appearance.
Conclusion
Live rock is more than just a decoration or simple filter; it is a dynamic, living element of your reef tank that plays a crucial role in the ecological and aesthetic success of your marine aquarium. By choosing the right type of live rock and maintaining it properly, you can create a thriving, beautiful aquatic environment that mimics the natural wonders of the ocean, providing a sustainable and enriching habitat for all its inhabitants.
