How to Kill Algae Fast

Algae are complex-celled photosynthetic organisms that often grow in aquariums, even clean and healthy tanks. The color of algae in an aquarium can indicate the condition of the water and tank. For example, green algae indicates a healthy tank but red or brown algae can sometimes indicate a problem with the water's quality. Though algae can be destroyed, the best solution is to control algae growth; chemicals and cleaning will not fully prevent algae growth in the future.

Things You'll Need

  • Bucket
  • Fish net
  • Clean rag
  • Algae pad
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Instructions

  1. Clean the Tank

    • 1

      Fill the bucket with water from your aquarium (add water from a tap if you have a large number of fish). Use the fishing net to capture the fish from the tank and transfer them to the water bucket.

    • 2

      Remove any plants, decorations and gravel from the tank. Switch off the filter system and remove it from the tank. Pour any remaining water from the tank into the sink.

    • 3

      Use an algae pad, which can be purchased from pet stores, to clean the inside of the glass until it is free of algae. Clean your filter system, too; refer to filter manual for correct cleaning instructions.

    • 4

      Wash all aquarium decorations, gravel and plants under cold running water. Use a clean rag if necessary to remove all dirt and grit. Refill the tank and replace the fish.

    Controlling Algae Growth

    • 5

      Move your tank away from windows or powerful lighting. Algae are photosynthetic organisms and require light to grow; removing direct sunlight will control algae growth and turning aquarium lights off at night will also discourage algae growth.

    • 6

      Replace plastic plants with living plants. If there is any additional light in your aquarium the living plants will compete with the algae and soak up remaining sunlight without turning your aquarium glass slimy and green.

    • 7

      Frequently clean the filter system to prevent red or brown algae and to ensure the water is fresh. Clean your tank whenever signs of algae begin to appear.

    • 8

      Do not overfeed your fish. Uneaten food will provide extra nutrients for algae, which will encourage algae growth and produce more waste in your tank.