How to Keep Algae Out of 50 Gallon Ponds With Fish

Algae builds up in fish ponds from fish waste, dead leaves and wood, and dead fish, to name a few causes. This green algae comes mostly in two forms, plankton algae and filamentous algae. You want to keep algae that lightly covers rocks for your fish to feed on, as it helps oxygenate the water and gives a natural look to the fish pond. The most common cause of unwanted algae is too many fish.

Things You'll Need

  • Submerged plants
  • Floating plants
  • Nitrifying bacteria
  • Organic pond water colorant
Show More

Instructions

  1. Keeping Algae Out of Fish Pond

    • 1

      For a 50-gallon fish pond, you should have 50 to 70 percent plant coverage on the surface. Plant both submerged plants and floating plants, such as water hyacinth, in your pond. Do not empty out the entire pond to do this. Be sure to refill if needed with non-tap water.

    • 2

      Add nitrifying bacteria to your pond. This will feed on the same food the algae feeds on, thus starving the algae. Make sure it has a place to feed, such as a bio-filter, rocks and plants.

    • 3

      You can use an organic pond water colorant in the water of your pond. This will help block out sunlight and thereby keep algae from growing.

    • 4

      Pull out dead leaves daily. Also, you can pull out algae from your pond for upkeep.