How to Remove Algae From the Walls of an Empty Fish Tank

Algae grow in a fish tank because they thrive on the same things that aid the other living things in the tank: nutrients and light. Too much light, whether natural light, such as sunlight, or artificial light can cause algae to grow. The warmer the water -- usually heated by light, and nitrates, which form from the waste created by the inhabitants of the tank -- can cause algae to grow quickly. Although algae can be removed from the tank without removing the marine life and water, they can also be removed safely while the tank is empty.

Things You'll Need

  • Cloth
  • Aquarium scraper
  • Paper towel
  • Vinegar
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Instructions

    • 1

      Wipe the inside of the glass with a damp cloth and remove what you can. Rinse the cloth of any algae and repeat.

    • 2

      Scrape from the bottom upward with an aquarium scraper (which is designed not to mar the glass or transparent plastic finish) and rinse the scraper under running water. Remove any algae scrapings that fall to the bottom of the tank or remain stuck to the sides, using a paper towel.

    • 3

      Pour a small amount of white or apple cider vinegar onto a clean cloth. Wipe away any remaining algae. Use the aquarium scraper to remove any algae loosened by using the vinegar. Use a clean, damp cloth to wipe away any vinegar residue, which can change the tank water's pH level, before adding water back into the tank.