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Home > Goldfish > Can Goldfish Eat Duckweed? Vet-Reviewed Nutritional Facts & Info!

Can Goldfish Eat Duckweed? Vet-Reviewed Nutritional Facts & Info!

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Duckweed is the perfect snack for goldfish and it is completely safe to grow and feed to your goldfish. Goldfish seem to love this green floating plant that is not only easy to grow but also very nutritious.

There are many different aquatic plants that you can grow in a goldfish aquarium, but goldfish seem to enjoy the accessibility and texture of duckweed over other plants.

If you would like to learn more about how safe duckweed is for goldfish and how you can easily grow this floating plant in their aquariums, then this article has all the answers you need!


Is Duckweed Safe for Goldfish To Eat?

Yes, duckweed is quite safe for goldfish to eat. This fast-growing plant forms a lush green carpet across the surface of the tank with flat, small green leaves and a short stem-like root that dangles below the water. It has no properties that would make it poisonous to goldfish, and they generally have an easy time digesting this plant.

Duckweed can be viewed as a type of grass that grows at the surface of your goldfish aquarium, which makes it easy for goldfish to eat the small pieces. Since duckweed grows so fast, allowing it to float freely and grow in your goldfish tank will help keep the duckweed from growing out of control, especially in brightly lit environments.

Duckweed is rich in protein and fiber, which makes it a great addition to your goldfish’s diet. It is especially good to feed to goldfish that are prone to bloating (which can lead to swim bladder issues) as the nutritional content of duckweed can help goldfish pass their waste more efficiently.

Goldfish are omnivores, so vegetative matter forms part of a healthy goldfish diet. A goldfish’s diet should be varied and not only consist of commercial pellets or flakes. Supplementing your goldfish’s diet with a natural source of protein and fiber such as duckweed is a great idea if you want to keep your goldfish’s digestive systems healthy and functioning properly.

Many goldfish die as a result of improper feeding, diet, and/or portion sizes – which can be easily prevented by proper education.

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Can You Grow Duckweed In A Goldfish Aquarium?

You can easily grow duckweed in a goldfish aquarium because this plant is beginner-friendly and easy to care for. It is considered an invasive plant because duckweed grows fast under the right conditions. Growing duckweed in a goldfish tank is simple in terms of the products and lighting conditions you will need to ensure your duckweed population flourishes in your goldfish aquarium. This aquatic plant does not require any fertilizers or CO2 to stay healthy—the only requirement for this plant is to ensure that you have a bright artificial light a few inches above the waterline for a minimum of 6 hours.

close up of duckweeds
Image Credit: DVY714, Shutterstock

These are a few of the benefits of growing duckweed in your goldfish aquarium:


Benefits of Growing Duckweed in Your Goldfish Aquarium

1. Better Water Conditions

Duckweed does a good job at removing waste products produced by goldfish that can be found in the water column. Goldfish are notorious for being messy fish that produce a lot of waste which increases the ammonia and nitrate levels in the aquarium. Duckweed helps by absorbing the nitrates from the water and using it as a nutrient to grow while keeping the water clean for your goldfish.

home aquarium
Image Credit: Tatiana Volgutova, Shutterstock

2. Provides Shade for Goldfish

Goldfish can sometimes become sensitive to bright artificial lights over the aquarium. These can cause them to become inactive and hide more frequently, as they may instinctively feel exposed and in danger from predators. Duckweed can act as a form of shade to block out the harshness of the light, however, this can cause issues for other live plants in the aquarium that have high lighting requirements.

Duckweed grows faster when it has access to more than 6 hours of bright light, so if you have a bright light shining down into your aquarium, you may notice that the duckweed grows at a more rapid rate. It’s best to place a small barrier or a partition of sorts in order to have a “shady” area in your tank and a bright area. The latter can be where other plants grow, and it will also provide a bright area for goldfish that wish to swim there.

3. Help To Prevent Duckweed From Overgrowing In An Aquarium

Since duckweed grows rapidly in the right conditions, allowing your goldfish to eat it will help to keep the duckweed from overpopulating your aquarium. Goldfish seem to enjoy grazing on this plant, and you do not have to worry about your goldfish eating all this plant at once because it will grow quicker than they can eat it, especially if you have the entire surface of the tank carpeted with duckweed.

Image Credit: zoosnow, Pixabay


Preparing Duckweed for Your Goldfish

Not much preparation goes into feeding your goldfish duckweed. If you choose to grow a thick carpet of duckweed in your goldfish aquarium, they will naturally snack on it throughout the day. However, if you find that your goldfish are eating too much duckweed at a time, then you can grow the duckweed in a separate body of water with a grow light, scoop duckweed from the surface, and place it into your goldfish aquarium every couple of days.



Duckweed is an inexpensive and safe snack for goldfish to graze on. It is both safe for them to eat and for it to be grown in their aquarium. This versatile aquatic plant has many benefits for goldfish and your goldfish will appreciate being fed this healthy and nutritious snack!

Featured Image Credit: hvqui, Pixabay

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