How to Cure Your Own Rocks for a Saltwater Tank

"Live rock" for saltwater aquariums is simply a portion of a coral reef that breaks apart from the reef formation. Live rock gets it name due to the small living crabs, worms and crustaceans that live in the rock. Fish hobbyists like to use live rock in aquariums because it provides several benefits. The texture of live rock is porous; it acts as a natural filter for your saltwater. Fish enjoy hiding in the crevices and eating the food that grows out of live rock in spectacular, bright colors. To make live rock ready for the fish, you have to cure it. Curing live rock is the process of saturating the dried fibers so it comes back to life, allowing growth. The process in turn releases ammonia and nitrites, which naturally occur in the dried fibers of the rock. The purchase price of uncured live rock is about one third of the cost of cured live rock.

  1. Materials Needed

    • The materials you will need to cure your live rock are an old toothbrush, leather gloves, a plastic container, pre-mixed salt water, an aquarium thermometer, an aquarium pump, a protein skimmer and a water test kit for ammonia and nitrite levels.

    Curing Live Rock

    • Put on leather gloves to protect your hands from cuts on the sharp surfaces of the live rock. Brush the rock with an old toothbrush gently to remove any loose film or dead portions of the rock.

      Place the rock in a plastic container. Add pre-mixed saltwater with a specific gravity of 1.021 to 1.025 to completely cover and surround the rock. Add an aquarium heater to the container and turn it on 80-degrees Fahrenheit. Insert an aquarium pump into the container to provide constant water movement. Place the container in a dimly lit area. This prevents algae blooms from appearing on the rock.

      Remove the heater and pump from the container twice a week. Then pour the entire contents of saltwater out. Add pre-mixed saltwater back to the container, replace the heater and pump.

      Scrub any debris off the live rock gently with a toothbrush between each water change.

      Test the water weekly to monitor the levels of ammonia and nitrite. The levels will be quite high when you start curing the rock. When the ammonia and nitrite levels are zero, the live rock is ready for placement in your aquarium.

    Tips

    • Curing live rock in a plastic container makes it easy to do complete water changes without the need to suction particles out of an aquarium.

      As live rock cures, it emits a quite pungent odor. You may want to place the container in a spare bedroom or garage.

      The amount of curing time varies by the size and shape of your live rock.

    Warnings

    • Never place uncured rock into aquariums with marine animals, corals or fish. The elevated ammonia and nitrites will harm or kill other marine life.