Live Rock Basics

Saltwater rock is commonly known as live rock, yet it's neither alive nor rock. Live rock is actually dead coral skeletons that separated from the reef and became mineralized. The "living" portion of live rock is a patina of bacteria and other organisms that colonize and ultimately live within the rock. Live rock is used in saltwater aquariums for its beauty and biological filtration.

Buying Live Rock Before buying live rock you should be familiar with the different types and their sources. The general types of live rock are base rock, turf rock, worm rock, and reef rock. Reef rock is excellent for beginners, while base rock works well as - you guessed it - a base. Turf rock contains a lot of macro-algae and worm rock a lot of tubeworms. Fiji and Tonga are two of the primary sources of live rock. Fiji live rock is considered the best. It is very porous with excellent coralline coverage. Tonga rock is more branch-like and offers a different shape and visual texture.

Curing and Introducing Live Rock
All live rock should be cured since uncured rock can greatly strain an established saltwater aquarium. As live rock is shipped, many of the organisms it contains die or begin to die. Curing prevents organisms released during this process from polluting the aquarium.

There are many different methods available for curing live rock. (If your saltwater aquarium is already stocked, cure new live rock in a separate container filled with saltwater.) Begin by rinsing each piece in saltwater and removing any dead organisms and algae clinging to the rock. Then arrange the live rock pieces in your aquarium, or in a similar manner to how they will be positioned in your fish tank.

For curing to succeed, water movement and a proper temperature (about 72F to 78F) are critical, as is a protein skimmer. Provide no lighting for the first 10 days to prevent algae growth. Perform water changes once or twice a week and use a bristle brush to remove dead organisms. After 10 days, check ammonia and nitrite levels. When both levels are at zero, your live rock curing is complete.

If live rock was cured outside your fish tank aquarium it will need to be introduced once curing is complete. We recommend reading about aquascaping and design before positioning live rock. This will help you create an effect that is both beautiful and naturalistic. Live rock can also be chiseled or drilled to achieve a different look.