Are duckweed good for betta fish tanks?

In this blog we will discuss the compatibility between betta fish and duckweed plants in bettas tank.This comprehensive guide will help betta enthusiasts to have all the information regarding duckweed plants before adding that to bettas tank.


In this blog

  • Are duckweed good for betta fish tanks?
  • Duckweed plant
  • Water parameters for duckweed and bettas
  • Do duckweed keep bettas tanks oxygenated?
  • Do duckweeds maintain aquarium pH?
  • How to cultivate duckweed in aquariums?
  • How to maintain duckweed in aquariums?
  • Do duckweed and bettas need substrate?
  • Duckweed as fish food
  • Duckweed benefits
  • Why do duckweed turn yellow?
  • Are duckweeds suitable for bettas?
  • Summary 
  • Frequently asked questions
  • Reference 

Are duckweed good for betta fish tanks?

Live aquatic plants give your betta aquarium a very natural look. They can provide natural hiding and resting spots, which in turn can help your betta live a stress-free life.

Duckweed also gets some natural health and ecological benefits from maintaining live aquatic plants. Plants also help to reduce certain types of aquarium contamination and even introduce needed nutrients if they are properly set up together and cared for.

There are mixed opinions about keeping duckweed in bettas tank.Many owners of planted tanks have a love-hate relationship with duckweed.

On the one hand, duckweed is a unique surface plant that gives the tank the natural look of a wetland.Duckweed is also great for sucking up excess nutrients and helping betta and other surface dwellers feel less exposed to the water column.

Duckweeds consume a lot of nutrients and help to clean the water in the betta aquarium.This also keeps the level of algae low, which is very convenient.This plant can be added to most bettas tank setups as it can withstand the most common aquarium water conditions.

Bettas love floating plants, perfect for their bubble nests.When the male fighting fish is ready to breed, he creates a bubble nest and floating plants like duckweed help them during the whole process. 

These bubble nests will float at the very top of the tank and look like a cluster of small bubbles.Once created, male fighting fish often remain under the nest, waiting for the female to mate with them.

They can be grown anywhere, including 1 gallon tanks (~ 4 L). Great for nano aquariums.Duckweed is so small that even with the entire tank covered, your betta may still be able to stay on the surface.

Duckweed plant

Duckweed are the smallest known flowering plants.Individual plants consist of a single flat oval leaf (technically modified stem) less than 1/4 inch long that floats on the surface of still-moving ponds, lakes, and swamps.

In the wild, duckweed is an important food source for fish.It also maintains habitat by providing sufficient shade to control the growth of oxygen-depriving algae.

  • Kingdom: Plantae
  • Scientific name: Lemnoideae
  • Family: Araceae
  • Order: Alismatales

Water parameters for duckweed and bettas

Ideal water parameters for duckweed:

  • Optimal pH for duckweed is between 6.5 – 7.5
  • Degree of water hardness- Soft to hard,does not care about hardness.Can easily withstand soft or hard water.
  • Optimal Temperature 15 – 32 C (60 – 90 F)

Ideal water parameters for bettas:

  • Temperature: 75°-81°F (23.8°-27.2°C)
  • Ammonia and Nitrite: 0 ppm.
  • Nitrate: <20 ppm.
  • GH: 3-4 dGH (50-66.7 ppm)
  • KH: 3-5 dKH (53.6- 89.4 ppm)
  • pH: 6.5-7.5.

Do duckweed keep bettas tanks oxygenated?

Yes, duckweed does help in producing oxygen in aquariums and keep the tanks oxygenated.It not only produces oxygen, but also improves water quality by consuming carbon dioxide from the water column. 

Duckweed loves still water, so no aeration is required.Even if the tank is not moving, you can be sure that the oxygen level in the tank is good.

Due to their special labyrinth organs, bettas are extremely tolerant to low oxygen levels and poor water quality, a characteristic unique to the Anabantoidei suborder, which inhales surface air.

So you don’t have to worry about oxygenating their tanks, but it doesn’t mean you keep them in poor water chemistry.They can tolerate such poor water conditions to some extent but ultimately they might die off soon if left unattended.

Maintaining excellent water quality is extremely important to maintain bettas health.

Do duckweeds maintain aquarium pH?

Duckweeds survives at pH 5-9, but grows best in the 6.5-7.5 range. Efficient management tends to keep the pH between 6.5 and 7.In this pH range, ammonia is primarily present as the most easily absorbed N-type ammonium ion.

How to cultivate duckweed in aquariums?

Duckweed grows rapidly and floats on calm waters.Keep the water calm with little or no flow.If the water moves too much, the plants will not grow quickly.

If necessary, grow separately in rectangular containers 5 inches deep, 18 inches long and 12 inches wide or more with dechlorinated water,aquatic plant fertilizer, straws, pH meter and thermometer and small nets.

How to maintain duckweed in aquariums?

The best way to deal with duckweed is to remove it manually from time to time. In most cases, you will need to do this every week or every other week.

In aquariums, a hand or a net can be used; in a pond, it is best to use a skimmer on a windy day so that all the plants are pushed aside.

The advantage of this plant is that it is easy to grow and does not require special care. Beginners will love this.

Do duckweed and bettas need substrate?

Duckweed is a floating plant and bettas are surface dwellers, so substrate is not important to them.

If you are adding other tank mates like bottom dwellers and other live plants which need substrate for digging and finding their food there, then you can go ahead with fine sand or gravels in bettas tank.But it is not required in bettas tank.

Duckweed as fish food

Dried duckweeds contain the natural pigments and other nutrients that fish desire.Simply sprinkle dried duckweed on the surface of the water. 

To fortify the vegetable portion,it is advisable to add the dried duckweed portion along with the commercial fish feed during feeding.

Duckweed benefits

  • Cost-effective aquarium plants
  • Act as a water filter- Floating aquarium plants like duckweed bring a variety of benefits to the water. These advantages make your work as a fish keeper easier and offer your fish a more comfortable living space.
  • Plants work as living filters, making a dent in the amount of waste present in the water.
  • Helps in mosquito prevention- It controls mosquitoes too.
  • Prevents algae growth-Large numbers of healthy duckweed plants can compete with algae for vital plant resources such as light and nutrients to help control algae.
  • Reduces evaporation on bodies of water.
  • Virtually free animal feed- it is given as food to fish in the wild and some aquarium fish also eat them.

Why do duckweed turn yellow?

If the duckweed turns yellow, it may be undernourished or underlit.For example, they can survive with a moderate amount of ambient light. However,it can be a problem if the water column has low nutritional levels.

Are duckweeds suitable for bettas?

Having a larger tank with plants for your betta will make them happiest.Bettas love duckweed for two reasons.First, it’s delicious and provides them with the necessary nutrients.

Second, floating plants provide plenty of hiding places for fish.Bettas need lots of hiding space in their aquarium when they feel threatened or want to nap,such floating plants can help them in every way to feel safe and secure.

They also help male bettas in building their bubble nest during breeding & it also protects the newly hatched baby bettas and protects them from predators.


  • Duckweed is a small, free-floating green aquatic plant commonly found in slow-moving or slow-moving bodies of water.
  • Duckweed is an ideal aquarium plant for suppressing algae growth.It blocks the light, creating a green lush mat on the surface of the water. 
  • It not only blocks the growth of algae, but also prevents the growth of any rooted plants.
  • These tiny plants provide cover for young fish and can be used as reproductive aids for bettas to build bubble nests.
  • Excessive growth of duckweed can deprive fish and other plants of light and nutrients.Overgrowth is not a serious problem in a fish tank as you can easily control it.
  • Floating plants like duckweed consume nutrients such as nitrates and phosphates from water, but their photosynthesis produces oxygen in return.
  • Duckweeds are fast-growing plants that also serve as water purifiers.Removes nitrates and absorbs excess mineral nutrients, especially nitrogen and phosphates.
  • Some betta keepers still don’t prefer to use duckweed in bettas tank, because of its unwanted growth.There are mixed opinions about them and many betta keepers say no to duckweed in bettas aquarium.

Frequently asked questions

How quickly do duckweed grow?

Duckweeds can double their mass in 16 hours to 2 days under optimal conditions of nutrient supply, sunlight and water temperature.This is faster than almost any other higher plant.

How much duckweed is needed for a 10 gallon aquarium? 

One ​​serving of duckweed is a good start for a 10-gallon aquarium.

How much light do duckweed need for their growth?

If you don’t have enough sunlight, hang fluorescent lighting fixtures in the aquarium.Duckweeds require at least 6 hours of direct sunlight each day.

Are duckweed easy to care for in a bettas tank?

Yes, duckweeds are easy to care for and they don’t need extra ordinary maintenance.

Do duckweeds need a filter in a bettas tank?

Duckweeds can go without filters,as they act as natural filters but for bettas filters are very important ,so you have to install filters in the bettas tank to keep them healthy.