How to Control Algae in a Goldfish Pond

Algae and mold can build up to high levels in a goldfish pond, making the pond look unsightly. The algae will not harm the fish or organisms inside the pond, but many pond owners want to know ways to keep the algae from accumulating on rocks and the bottom of the pond. Newer ponds tend to have a heavy boom of algae, but in general this increase is beneficial, as it eats up excess nutrients. Before adding goldfish to a pond, allow the pond to create its own ecosystem for a week or two, then work on controlling excess algae.

Things You'll Need

  • Soft brush
  • Barley straw bundle
  • Pond or pool vaccum
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Instructions

    • 1

      Pull or pick out all excess algae you can reach with the soft brush. Also make sure your pond pump is not clogged and is working efficiently.

    • 2

      Add plant life to the pond, such as water lilies and other types of floating plants. These plants will decrease the amount of nutrients in the pond and allow less sunlight to enter the pond. This will reduce algae levels.

    • 3

      Place one barley straw bundle for every 1,000 gallons of water in the pond. These bundles will decrease the levels of nutrients for algae to feed on. Also add nitrifying bacteria to the pond to further starve algae.

    • 4

      Vacuum the bottom of the pond regularly. This will suck up loose algae and nutrients.