How to Clean an Aquarium That Has Cotton Fungus

Cleaning a fish tank is a job that's hard to look forward to. Unfortunately, a dirty tank may lead to fungal or bacterial growth. The cotton fungus, caused by the Flavobacterium columnare bacteria, is easy to spot. A common sign that your fish may be infected is gray or white cottonlike formations on their lips or faces. Proper cleaning and treatment help clear up the bacteria and give your fish a safe, clean home.

Things You'll Need

  • Algae removal tool
  • Gravel siphon
  • Bucket
  • Carbon
  • Antibacterial treatment
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Instructions

    • 1

      Unplug the pump and heater, and let them cool down for about 10 minutes. Clean any algae off the aquarium walls with an approved algae removal tool such as a magnet, scrubber or scraper. Slide a magnet alongside the outside of the tank to move algae on the inside. You'll use a scrubber or scraper inside the tank to clean the algae off the inside of the walls with direct pressure.

    • 2

      Siphon half of the water out of the tank into a bucket with a gravel siphon, which uses gravity to pull the water from the tank. At the same time, vacuum the gravel with the siphon and remove all of the organic waste that cotton fungus feeds on.

    • 3

      Remove the foam from the filter housing and clean it in the bucket of aquarium water. Replace the carbon in the filter that helps clean the tank.

    • 4

      Refill the tank with tap water. Make sure it is the same temperature as the water in the tank.

    • 5

      Add an over-the-counter antibacterial treatment, available online or at your local pet store, for cotton fungus to your tank. Administer the treatment as directed by the manufacturer's label.