Koi Pond Algae: 5 Solutions Koi Pond Algae: 5 Solutions

The scummy green color in pond water means that your Koi pond algae has become a problem. With the right tools, your pond will become clean, your fish will thrive and you will enjoy the serenity of your self-made masterpiece.

Solution 1 – Aerating plants

A simple, organic solution, some plants are designed to clean out the detritus that algae consume. Anacharis is elemental to a Koi garden. For small gardens, place one plant per every square foot of pond.  For larger ponds, place one bunch for every three square feet. Barley bundles or balls are available at many plant and fish stores and can be dropped into the pond with little preparation and great results.

Solution 2 – Shade

The more sun on your pond, the more algae you will accumulate. To provide shade for your Koi and eliminate excess UV, covering plants like lilies are excellent to keep your algae blooms under control.

Solution 3 – Feed Appropriately


Algae can’t survive if it has no food to eat. By feeding your Koi the appropriate amount of food, you guard against allowing algae to gorge themselves excessive nutrients that collect on the pond’s bottom.    

Solution 4 – Clean Regularly

To prevent algae from getting too comfortable, take the time to maintain your pond regularly. Scrub rocks, tiles, and pond liners when you change your water monthly, making sure to use hot water and an algae scrub if necessary.  

Solution 5 – Algae Killers

If natural solutions leave your tank as green as ever, move on to an algaecide from your nearby fish or garden store. Many different kinds of freshwater algae can be killed with this last-resort method including black beard algae. Any algaecide using the active ingredient polyethylene dichloride will take care of stubborn algae blooms.

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