How to Grow Coralline Algae on Live Rocks in Saltwater Aquarium Reef Tanks

Coralline algae is a hard encrusting algae, which grows on live rock and aquarium substrate. This attractive algae is found in numerous colors, including red, pink and purple. The presence of coralline algae discourages unwanted algae species from becoming established in a tank and makes for a pleasing display in any marine aquarium. Coralline algae is slow- growing and takes up to 10 weeks to become established in a marine aquarium. If attempting to grow coralline algae, omit sea urchins from the environment as they feed on this algae.

Things You'll Need

  • Marine aquarium
  • Protein skimmer
  • Canister or hang-on filter
  • Coralline algae scrapings
  • Live rocks
  • Coralline starter pack from an aquatic dealer
  • Hydrometer
  • 2 Triton 40-watt tubes per 55-gallons
  • 1 actinic or blue 40-watt florescent tube per 55 gallons
  • PH test kit
  • PH booster
  • Carbonate hardness test kit
  • Carbonate hardness booster
  • Calcium test kit
  • Calcium booster
  • Activated carbon pouch
  • Phosphate test kit
  • Phosphate remover pouch
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Instructions

    • 1

      Use a sharp blade to scrape the coralline algae from the glass panes of an existing marine aquarium. Such tanks are found at aquatic dealers or at the home of a local marine club member.

    • 2

      Turn off the protein skimmer and canister or hang-on filter, so as not to remove the coralline scrapings.

    • 3

      Pour the scrapings into the aquarium. The power heads blow the lightweight scrapings across the aquarium, where they settle onto live rocks and the substrate.

    • 4

      Wait for the coralline algae scrapings to settle out of the water column before turning on the protein skimmer and additional filters. The filters are able to be turned on within an hour.

    • 5

      Add three or four pieces of live rock that contain coralline algae to the aquarium. Add the rock in addition or as an alternative to the coralline scrapings. Live rock is marine rock that has algae and other encrusting marine organisms growing on its surface.

    • 6

      Add coralline algae from a commercial coralline starter pack, as an alternative or in addition to scrapings and live rock.

    • 7

      Use a hydrometer to check the specific gravity of the water, which must be 1.024. Add synthetic sea salt to raise the specific gravity, or dechlorinated water to lower the specific gravity.

    • 8

      Install two Triton 40-watt florescent tubes and one actinic or blue 40-watt florescent tube for every 55 gallons of aquarium water.

    • 9

      Use a marine pH test kit to measure the pH of the water. Use a commercial marine pH booster to raise the ph to 8.3, if required.

    • 10

      Use a carbonate hardness test kit to measure the amount of carbonate hardness, which needs to be between 9 and 12 dkh. Add a commercial carbonate hardness booster to maintain the level of carbonate hardness.

    • 11

      Use a calcium test kit to measure the amount of calcium in the water. Add commercial calcium in either liquid or powder form to maintain the calcium level at between 400 and 450 ppm.

    • 12

      Add a nylon pouch of activated carbon to the chemical filter compartment of the canister or hang-on filter. Carbon removes impurities from the water and thereby creates a healthy environment for the coralline algae to grow.

    • 13

      Test the levels with a phosphate test kit and keep the level as close to 0 ppm as possible, as coralline algae grows best in water with very low phosphate levels. Add a phosphate removing pouch to the chemical filter compartment of the canister or hang-on filter to control phosphates.