How to Make Life Rocks for Saltwater

Live rock is covered with invertebrate animals, such as sponges and algae. Beneficial bacteria also colonize these pieces of rock. The bacteria cultures that cover live rock break down toxic metabolic waste in saltwater aquariums, while the various organisms living on the rock make them aesthetically pleasing. You can make your own live rock by allowing living sponges and coralline algae to colonize pieces of sandstone or porous base rock. Sandstone is principally sedimentary rock composed of sand grains that are held together by calcareous material. Once other small reef creatures take up residence in holes in the rock, the sandstone will be indistinguishable from living rock.

Things You'll Need

  • Attractive piece of sandstone
  • Synthetic sea water
  • 5-gallon plastic bucket
  • 1-gallon plastic bucket
  • Established marine aquarium
  • Sharp knife
  • Thin, plastic cable ties
  • Living sponges and pieces of higher algae
  • Tiny crabs and sea stars
  • Cultures of beneficial bacteria
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Instructions

    • 1

      Locate a piece of sandstone that has a pleasing shape and is the size that you require. Sandstone can be found on a beach and can also be purchased from a marine aquarium dealer.

    • 2

      Remove any dying algae that may already be growing on the piece of sandstone.

    • 3

      Rinse the sandstone in a bucket of aged sea water to remove any sea sand that is lying in the holes and crevasses and any pieces of algae and other detritus that remains on the rock.

    • 4

      Fill the 5-gallon bucket halfway with synthetic sea water and place the sandstone in the bucket. Synthetic sea salt is available from most marine aquarium dealers.

    • 5

      Use a sharp knife to remove a small piece of live sponge from a piece of live rock in your existing marine aquarium. Place a 1-gallon plastic bucket into the aquarium and put the piece of sponge into the bucket. Do this under water as the sponge will not be able to rid its body of air if it is removed from the water. Purchase a piece of sponge from your local marine aquarium dealer, if you do not have an existing aquarium.

    • 6

      Place the 1-gallon bucket into the 5-gallon bucket and transfer the sponge to the 5-gallon bucket, under water.

    • 7

      Use a cable tie to carefully attach the sponge to the piece of sandstone.

    • 8

      Remove a number of pieces of higher algae from the live rock in your established aquarium. It is not necessary to transfer this under water.

    • 9

      Use cable ties to attach these pieces of algae to the sandstone.

    • 10

      Gather a number of tiny marine creatures, such as crabs and sea stars and place them on the piece of sandstone.

    • 11

      Place the sandstone into the 1-gallon bucket, under water and transfer the rock to its new destination. Bacteria from the sponge and algae will immediately begin to colonize the rock.