How to Get Rid of Red Slime in a Saltwater Aquarium

Red slime refers to a type of bacteria that can grow on the rocks and pebbles in a saltwater aquarium. Referred to by specialists as Cyanobacteria, the algae's more common name is actually misleading, as red slime's color generally ranges from dark green to blue and is only occasionally dark orange. Getting rid of red slime involves much more than cleaning the aquarium. Removal should also address the underlying causes of the bacterial infection, in order to avoid facing the same problem later.

Things You'll Need

  • Turkey baster
  • Skimmer cup
  • Carbon filter cartridge
  • Antibiotics (optional)
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Instructions

    • 1

      Wipe or scrape off traces of red slime from the pebbles and rocks at the bottom of your aquarium using your only your hands. If you also have sand or very small rock particles, use a turkey baster to carefully clean only the surface of your aquarium's sediment, rather than attempting to reach deeper layers. You may have to repeat this step once a day for up to two weeks in order to remove residual or recurrent red slime.

    • 2

      Replace your aquarium's skimmer cup, or thoroughly clean the existing one, if it is still usable. The most effective way to clean a skimmer is by using the bristles of a brush.

    • 3

      Replace your tank's carbon filter in order to keep nitrate, phosphate and silicate levels in your aquarium low. High concentrations of any of these three elements may lead to red slime.

    • 4

      Inspect larger aquariums on a regular basis for decomposing organisms, particularly dead clams, and remove these from the water.

    • 5

      Apply antibiotics purchased from pet stores sparingly to the aquarium in the case of recurrent or serious cases of red slime. Antibiotics should serve as a last resort solution, as they can harm or kill other saltwater organisms.