How to Combat Red Algae in Your Salt Water Aquarium

Red slime algae, or cyanobaceria, forms when there are excess levels of dissolved organic carbons in your fish tank. This algae bloom is common in newer aquariums, but can develop in older, more mature aquariums as well. The most common cause of the algae bloom is overfeeding. If not taken care of properly, this algae will spread and suffocate everything in your tank. Here are a few ways to combat this algae.

Things You'll Need

  • Saltwater (made with reverse osmosis water)
  • Granular ferric oxide
  • Cyanobacteria remover
  • Hermit crabs, snails, fighting conch
  • Protein skimmer
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Instructions

  1. Treating your tank

    • 1

      Ask your local fish store for red slime remover. Red slime remover usually comes in a powder form and can be added to your tank by dissolving it in fresh water first. Follow all directions on the package.
      Once you dose your tank, let the remover work for 48 hours.The remover works by accelerating the solubilization and biological digestion of organic solids. This process will increase the demand for oxygen in your tank. Make sure your tank is able to handle this excess demand.

    • 2

      Change your water after the time period has expired. You must change 20% of your aquarium's water after each treatment. After changing the water, add in your clean-up crew. Hermit crabs and snails will sift the sand, and clean any dead debris. Have one hermit crab or snail per gallon of water in your tank.

    • 3

      Keep an eye on your tank over the next few days, if the problem returns, add granular ferric oxide (Phosban) to the sump of your tank. This will reduce phosphates in your tank, and help restore the balance. If the problem continues, add your protein skimmer to the sump or back of your tank. The protein skimmer will pick up any organic matter. These steps should get rid of your red algae bloom. If not, you'll have to dismantle and thoroughly clean your tank.

    • 4

      There is no quick fix for cyanobaceria. Combating this problem will take a lot of time and effort.

      The goal is to limit the amount of dissolved organic carbons in your tank. If you do not do so, the red slime will always return.