How to Control String Algae in a Saltwater Tank

Sea water algae, such as string algae, are dependant on nutrients and light in order to thrive. Nutrients are typically high in marine aquariums, as both the fish and invertebrate animals, such as living corals and anemones, put their metabolic waste into the aquarium water. Invertebrate animals also require intense light levels in order to survive; string algae uses this light to multiply. Suitable filtration and regular water changes are valuable in combating string algae, as these methods will remove excessive nutrients from the aquarium water. It is however hard to limit light in a saltwater tank as the invertebrate animals will die if they don't receive enough light.

Things You'll Need

  • Protein skimmer
  • Canister filter that incorporates mechanical, biological and chemical filter material
  • Chlorine neutralizer
  • Synthetic sea salt
  • Bucket
  • Stiff bristle brush
  • Aquarium magnet
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Instructions

    • 1

      Install a protein skimmer that has been rated for the volume of your aquarium. Use a free standing unit and place this skimmer into the sump, which is a remote reservoir or container that is positioned below the aquarium and connected to it, via piping.

    • 2

      Service the skimmer regularly by emptying the collection cup and wiping the neck section of the unit so that foam can continue to easily push nutrients from the water.

    • 3

      Install a canister filter on the aquarium. Ensure that this filter has mechanical, chemical and biological filtration material.

    • 4

      Clean the canister filter on a regular basis. Rinse or replace the mechanical filter material weekly. Although this floss or matting has physically trapped detritus and debris, the material is still in the water and adds nutrients as it decomposes.

    • 5

      Replace the activated carbon on a monthly basis. This chemical filter material removes waste products from the water, but eventually becomes exhausted and leaches waste back into the water.

    • 6

      Include a high quality biological filter material in the biological filter compartment. Use a material that is porous so that not only aerobic or oxygen loving bacteria can grow on its surface, but than anaerobic or bacteria that require an oxygen depleted environment can thrive within the pores. The anaerobic bacteria will remove nitrates which string algae require as nutrients, from the water.

    • 7

      Do weekly 10 percent water changes. Mix synthetic sea salt with tap water that has been pretreated with a product to neutralize chlorine. By changing a percentage of the water, nutrients are diluted.

    • 8

      Remove as much of the string algae by hand, as possible.

    • 9

      Remove aquarium décor and place in a plastic bucket containing water from the aquarium. Remove the string algae using a stiff bristle brush. Rinse the décor in the water and return to the aquarium.

    • 10

      Use an aquarium magnet to remove any string algae from the glass panes of the aquarium. An aquarium magnet comprises two magnets, which are covered with strips of material. One is placed on either side of the glass and when the one on the outside is moved, the magnet on the inside cleans the glass pane.

    • 11

      Feed the fish and invertebrate animals sparsely.

    • 12

      Remove a number of the fish or invertebrates if the problem persists.