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5 Efficient Ways To Control Algae In Your Koi Pond

You Can Keep Your Backyard Pond In Des Moines Clearer And Cleaner

Nobody deserves to have an algae pit for a koi pond.

Especially not you.

You don’t want to have an eyesore where your koi pond used to be.

And you don’t have to.

We want everyone to know the best ways to control algae for their koi pond.

Here are our 5 favorite methods for controlling pond algae:

  1. Have a properly functioning pond
  2. Use living algae filters
  3. Use mechanical filters
  4. Add rocks and gravel
  5. Use algae treatments/water clarifiers

Let’s learn how you can use these to keep algae from taking over your koi pond.

But first, you may want to know what type of algae you’re dealing with.

Here are a few other koi pond questions and answers >>

Algae bloom floating in the middle of a koi pond

Make Sure You Know The Algae You’re Dealing With

You have 2 types of algae which can have different clearing methods.

Planktonic (suspended) algae are what makes your water look green.

Filamentous (string) algae look like strings of, well, algae. It forms in hair-like masses, attaching itself to rocks, plants, or other available surfaces.

You may find it harder to get rid of string algae than planktonic.

String algae have several different ways of growing and seeding, so you need to get rid of all of it at once.

A good point to keep in mind: your pond needs algae.

A little bit of algae, usually on the bottom, is good for ponds.

If it works in nature it should work in your backyard.

Up close picture of pond algae

1. Make Sure Your Pond Works Smoothly

Your pond could be full of algae because something isn’t working right.

If it isn’t, algae will come back no matter what you add into it.

Start by checking if your pond is collecting runoff water.

This means rain is flooding your pond with organic materials that fuel algae growth.

Put a stop to this if it is happening.

You should also ensure your pond’s filters and water flow are a good match for the size of your pond.

If they aren’t, your pond won’t be able to filter all the water.

Which would be perfect for algae.

Diagram of the parts of a working pond

2. Use Living Algae Filters

You can use living creatures to help control algae in your koi pond.

They either eat the algae or the nutrients it feeds off of.

You have a few options when it comes to living algae filters:


Fish are a fun addition to any pond!

Not only do they look cool and are fun to feed, but they also love algae (especially string algae).

Explore these 7 amazing species of fish for your backyard pond >>

Aquatic Plants

Aquatic plants are beautiful and control koi pond algae in a few different ways:

  • Floating plants block the sunlight that helps algae grow
  • Submerged plants add oxygen to the water
  • All aquatic plants eat algae nutrients

Hello beautiful pond plants, goodbye algae.

Take a look at these 7 beautiful aquatic plants for your backyard pond >>

Koi pond with plenty of aquatic plants to control algae

Beneficial Bacteria

These bad boys live on rocks and gravel in your pond.

They help keep your water clean and clear.

You can add them into your pond yourself or wait for them to build up naturally.

New ponds can start gaining algae at first, but when the bacteria builds up enough it can fight it off.

You can also add a biological waterfall filter (biofalls) to give more space for the beneficial bacteria to grow.

3. Install Mechanical Filters

One example is a skimmer.

It skims larger debris like leaves and sticks out of your pond for you.

Now the debris won’t sink to the bottom and turn into waste perfect for breeding algae.

Pond skimmer basket and filter mat needing a cleaning after helping control algae

You can also use an automatic dosing system like the IonGen.

It keeps your pond clear without using chemicals.

4. Add Rocks And Gravel

You will be providing a better place for beneficial bacteria to set up shop.

They have a larger, better surface area than a smooth liner.

Plus they look amazing in koi ponds.

Water splashing down rocks

5. Use Algae Treatments/Water Clarifiers

If you have fish and plants make sure the treatment is safe for them!

These treatments bring waste particles together, making them big enough for removal.

You can remove it yourself or let the filters take care of it.

Treatments can include:

  • Greenclean (all-natural)
  • AlgaeFix (EPA approved safe for plants and fish)
  • Sludge Remover Bacteria (targets the organic material)

Targeting the cause of the algae is important too, otherwise, it’ll keep coming back.

Prevention Is The Best Method

You won’t ever have to worry about algae if you never let it happen.

If you have all of the previously mentioned parts a pond needs, algae shouldn’t appear so readily.

You can also add elements to your pond to prevent algae.

For example, you can use Koi Clay to add minerals and remove toxins.

Help keep your pond healthier and better looking.

You can use an automatic dosing system to control algae growth in your pond >>

Control Algae And Enjoy Your Koi Pond

You can fight off and prevent algae from bothering your koi pond! All it takes is a little knowledge and some materials. You can also fight algae off and provide more area for your pond by including a wetland filtration system.

Find out how wetland filters work to control algae and add beauty to your pond >>