Q. What is Live Rock?
A. The main misconception is that the rock itself is alive. The rock is made up of calcium carbonate skeletons of long dead corals or other calcareous organisms. What makes it live is all the organisms living on it or in the crevices. Most of what is alive is bacteria which feed off the waste the fish produce. There also can be snails, crabs, worms, shrimp, sponge, and even algae living or growing on it. So when someone refers to live rock they are referring to rock that has living organisms on it.

Q. Why do I need Live Rock?
A. The main reason live rock is the key to a saltwater aquarium is that it provides a home for different kinds of bacteria. These bacteria break down fish waste from ammonia all the way down to nitrogen gas which gets released from the tank. Live rock is by far the most efficient biological filter and is of course the natural one. An important note about live rock is that it goes in to the main part of the tank. Unlike most hang on biological filters or wet/dry filters, when the power goes out, the live rock is still able to act as a filter since it is still in the tank with the fish.
Live rock is the main formation of the reefs out in the ocean and the main biological filter. Live rock provides a home for the fish and a foundation for most corals to grow on. Just like humans need a home to live in, most sea creatures need rock to provide them their home. Many fish do not do well in an aquarium without having hiding places. When fish do not have places to hide, such as those provided by live rock, they get spooked and stressed-out, which often leads to them getting sick and even dying. Corals also need a structure to live on and live rock allows them to be placed in a tank according to the specific environment they require.

Q. What is the difference between cured live rock and uncured live rock?
A. Uncured live rock is the result of shipping. After the rock is harvested from the ocean it gets boxed up and eventually sent to our store. That process causes some of the organisms on the rock to die off. Once the live rock gets put back into saltwater, the dead organisms decay and pollute the water. The dying organisms produce waste the same way fish do. The bacteria that grow on the rock to feed off the fish waste also grow to feed off the waste of the dying organisms. This process is referred to as cycling. Cycling a tank can take a few weeks because there are different kinds of bacteria that have to grow to break down the different forms of waste. After the cycle has finished and the rock is no longer producing waste and is in a state of breaking down waste it is considered cured.

Q. I heard that I can buy cured rock over the internet. Is that true?
A. It is true that the rock you are buying may be cured. However, since it is the shipment process that causes live rock to become uncured, there is very little chance that it will still be fully cured by the time it gets delivered to your house. Rock that is shipped in water has a greater chance of arriving cured, but the considerable freight cost increase makes this an unwanted option for most hobbyists.