How to Culture Live Rock

Live rock isn't really alive---the name refers to the, bacteria, algae, corals, sponges, and other small invertebrates that live in the many pores of the rocks themselves, which are usually made up of the skeletons of long-dead corals. You can use live rock not only as the main filtration system, but to provide shelter for fish while adding to the aesthetic appeal of the aquarium. Before introducing live rock in your aquarium, it has to cured, a process that removes dead or decaying matter. This is important because decaying organisms can cause a spike in nitrite and ammonia levels.

Things You'll Need

  • Large container for curing rocks
  • Saltwater
  • Nitrite and ammonia test kits
  • Aquarium pump
  • Aquarium heater
  • Brush and tweezers
  • Siphon hose
  • Heavy plastic sheeting or newspaper
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Instructions

  1. The Curing Process

    • 1
      Harvested coral

      Obtain rocks from a reputable aquarium where the rocks have either been cultivated in the store or in an ocean facility where they have been tended in an area as close to their natural environment as possible. Harvesting rocks yourself can introduce undesirable bacteria, mollusks, clams and other unwanted organisms to your marine setup.

    • 2

      Prepare a container for the rocks. A larger number of rocks may be cultivated in a plastic kiddie pool, Rubbermaid tote or trashcan. Dilution by way of a larger container will not only protect the living organisms in your rocks from the dangerously high ammonia levels that can result from decay, it will help your rocks cure more quickly. Fill the container with saltwater. Use a thermometer to maintain a temperature in the low 70s. Install a pump to circulate the water.

    • 3

      Submerge freshly obtained live rock into the container and swish it around to loosen and remove any visible dead or dying organisms. Use tweezers or a brush to remove dead matter that doesn't dislodge from the rock by itself. Use caution not to damage any living organisms.

    • 4

      Siphon out organic matter as it appears during the curing process. The easiest way to tell if the rock has cured, is by the smell of the water. Once the foul smell has dissipated and no organic matter can be seen, use the test kit to ensure a zero reading. Maintain a water temperature in the low 70s to ensure the health of living organisms.

    • 5

      Wrap the rock in plastic sheeting or wet newspaper to protect any living organisms during transport from the curing receptacle to your aquarium. The curing process may take a few days or a month depending on the amount of dead and decaying matter on the rock.

    • 6
      Live rock in a marine aquarium

      Culturing begins when the rock is installed into your aquarium. If the rock is completely "dead," you must introduce a source for new organisms. This is usually done by adding the rock into an aquarium that already has "living" rocks or sand that will seed the new rock, or by using maturation fluid, which contains the bacteria needed to maintain the proper nitrite and ammonia levels in your tank. However, simply using maturation fluid will not introduce the organisms that can beautify your tank, such as corals. These can only be obtained from actual live rocks.