How to Remove Duckweed and Restore Your Beautiful Pond?

When you’re caring for ponds on your property, there are a lot of things to be mindful of. Plant and animal life in your pond is a delicate balance, and if one overwhelms the other you can have problems. Every spring and summer, many pond owners have to deal with duckweed.


How to Remove Duckweed and Restore Your Beautiful Pond?How to Identify DuckweedIs Duckweed a Bad Plant or Not?How to Control Small Populations of DuckweedHow to Remove Large Populations of DuckweedWhat to Do with Removed DuckweedConclusion


How to Identify Duckweed

Duckweed is a very small plant that floats on top of ponds, lakes, or other still water. You can identify it by its appearance. This plant is tiny, no larger than a quarter of an inch in total, and usually consists of only 1 to 3 leaves. Each little plant has its own short roots coming from the bottom.

These are free-floating plants that stay on the surface of your pond. Even during the winter, they can still remain green and floating, although they will mostly die out. In warm weather, duckweed can form a layer like a carpet on the top of still water.

Is Duckweed a Bad Plant or Not?

There is a lot of debate among pond owners about whether or not it’s bad to have duckweed in your pond. At the end of the day, the answer seems to be that it’s not bad unless it covers the pond. The problem with duckweed is that each plant can reproduce and create an entirely new plant in around 24 hours when the conditions are good.

When your pond is entirely covered with duckweed, the little plants will block sunlight from getting into the water. This will cause most other water-dwelling plants to die off, eventually creating an unhealthy environment for all the other plant and animal life within and around the pond. However, the environment created will make the duckweed thrive even more, because they feed off of nutrients like phosphorous and nitrogen from dead organic matter on the bottom of the pond.

However, in smaller amounts duckweed can actually be healthy for your pond. These little plants help to balance out the nutrients in your pond to keep a good eco-system going for the fish and plants that live there. It can even look pretty in small quantities floating around your pond. Only when it covers the entire surface of the pond is it unhealthy and ugly.

In some situations, duckweed is a very desirable plant. Small pond owners will sometimes introduce duckweed into their ponds intentionally. This is partially because of its ability to help balance out your pond, but also because duckweed is the natural food for some types of fish and birds. If you have grass carps or koi fish, duckweed will be a welcome addition to your pond.

How to Control Small Populations of Duckweed?

If you don’t mind the duckweed, you can allow the seasons themselves to regulate it, as the plants will die off when the weather cools down. Usually they will grow again once things start to warm up, as they will have deposited seeds on the bottom of the pond. However, this might not be practical for you if the duckweed is already covering your pond and causing problems for the eco-system.

Before your duckweed gets out of control, there are things you can do to keep it contained. The best way to avoid a problem with duckweed is to prevent it from getting the explosive growth it’s known for during the spring and summer. You may not be able to avoid having duckweed introduced into your pond, but you can control the duckweed that does come.

There are a few natural methods of controlling duckweed and a few chemical methods. Most chemicals are not healthy for your pond and are quite expensive. Natural removals can take up a little time, but they are highly effective.

For natural control, you need to remove plants every week to keep the popular down. This can be done with a pool skimmer, rake, or a water boom on larger ponds. Removing the plants from the water will kill them and help to control the amount of duckweed you get. You can also install a water fountain in small ponds to keep the water moving around, because duckweed cannot survive well on moving water. Lastly, it’s also possible to get fish or birds in the area that will eat duckweed, such as grass carp or koi fish.

You’ll get the best results from a skimmer designed to take out duckweed, such as this Parachute Skimmer.

But, you can still get good results from a regular pool skimmer like this Pool Supplies Express model.

Here are a few chemical products that can be used for duckweed control:

Tsunami DQ Aquatic Herbicide 


Reward Aquatic Herbicide, Broad Spectrum


How to Remove Large Populations of Duckweed?

Once the duckweed has covered your pond, there is really only one thing you can do about it. You will have to remove it from the surface of the pond and physically take it out of the water. Using a duckweed skimmer like I mentioned above is the best way to remove the little plants. They are extremely easy to take out of the pond, because they aren’t rooted down to anything. You shouldn’t have any problem removing them, but it will still take a few hours depending on the size of your pond.

For large ponds, a boom is recommended to keep the duckweed contained in a smaller area so you can continue removing it without any trouble.

Check out this video about removing duckweed from your pond:

What to Do with Removed Duckweed?

When you take the little duckweed plants out of the water you don’t have to just throw them out. You should make sure they’re far enough from the pond to wash back into it, but instead of leaving them on the ground or throwing them away you can make sure of them.

Duckweed can be composted effectively to turn into healthy soil for your yard. It can also be spread around your garden and used like mulch. Even if you decide to leave it on the grass nearby your pond, it can still help with grass growth, and you will be able to mow over it to help chop it up and keep it from returning to your pond again.


Duckweed can be a real nuisance if it gets out of control in your pond. Dealing with it isn’t necessarily difficult, but it can be time-consuming or expensive. It’s best to keep an eye on the duckweed growing in your pond and to maintain it weekly before it can grow into an enormous population.

I hope the methods I just talked about will help you to get rid of your duckweed and keep your pond healthy and beautiful! Do you have any other tips about controlling duckweed? Let me know down in the comments!

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