How to remove algae from a wood deck

Wood decks are recognised for their durability and rustic appeal. Shaded portions of decks in humid environments create ideal conditions for algae growth. Nearby ponds and streams also contribute to algae on wood decks. Black algae streaks discolour decks and cause them to appear dingy. Promptly treat affected wood decks to preserve their aesthetic appeal and prevent permanent stains. With proper care, wood decks can maintain their appearance for many years. Remove algae from a wood deck using certain supplies.

Fill a clean plastic bucket with 1 gallon warm water. Pour 177ml. powdered oxygen bleach into the water. Thoroughly mix the solution. Wait 10 minutes for the powder granules to completely dissolve in the water.

Pour the oxygen bleach solution into a hand pump sprayer. Spray the solution liberally onto the algae. Allow the solution to work for 15 minutes.

Scrub the deck with a nylon scrub brush to remove the algae. Remove as much algae as possible.

Attach a spray nozzle to a garden hose. Spray water from the garden hose onto the deck to rinse away the oxygen bleach solution and algae growth.

Repeat the cleaning process until all traces of algae are completely removed from the deck. Allow the deck to air dry after the final rinse.


Prevent algae growth by trimming overhanging branches and shrubs surrounding the deck.


Do not use chlorine bleach on the deck; the wood may become discoloured and damaged. Do not remove algae with a pressure washer; the deck may be permanently scarred from the high water pressure.

Things You'll Need

  • Clean plastic bucket
  • 1 gallon warm water
  • 170gr. powdered oxygen bleach
  • Hand pump sprayer
  • Nylon scrub brush
  • Spray nozzle
  • Garden hose
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About the Author

April Dowling first started writing in high school and has written many news articles for newspaper and yearbook publications. She is currently pursuing a career as an online writer and affiliate marketer. Dowling writes for several websites and keeps many blogs.