Java Fern in Betta Tank

If you are an experienced aquarist, you are surely familiar with the Java fern. If you have just began keeping Betta fish, read on to see if the Java fern is good for keeping in a Betta tank.

One of the easiest to care for aquarium plants, the Java Fern is very popular in Betta tanks. This plant mimics their natural environment, as they usually live in the shady tropical waters in Malaysia, Thailand, parts of China and other South Asian countries.

What is the Java Fern?

The Java Fern (scientifically called Microsorum pteropus) is a very popular, low-maintenance live aquarium plant from South East Asia that comes in a wide range of varieties. This plant is one of the best plants for beginners and will quickly spread like a weed if kept in good conditions.

The Java Fern belongs to the Polypodiaceae family, together with over 60 distinct genera. The most widespread are the needle leaf, lance leaf, narrow leaf or Windelov.

It is a green plant with long, pointed leaves of a leathery texture and can reach up to 14 inches (35.6 cm) tall. It grows fairly slowly, about 1 inch (2.5 cm)/month.

Tank requirements

Java Ferns don’t need any special growth conditions. They can be kept in tanks as small as 10 gallons and thrive in low light. They are jungle plants naturally living in dark environments. The best tank for them should mimic a damp tropical forest biome.

The plant needs about 6 hours of natural light per day. Lower light is always better than brighter one, as bright light may “burn” the leaves, leaving transparent or brown spots, which will have to be removed. It is best to use subdued fluorescent bulbs or small incandescent ones, usually provided for small aquariums.

Many times, a well-lit room with a wide window is everything a Betta tank needs, and Java ferns will do just great with a few hours of light each day. It is best to use artificial light only when necessary.

Keep your Java Fern in freshwater between 68 – 80 degrees Fahrenheit, and pH between 6-8. Bettas need slightly more acidic water, so a pH of 7 – 7.5 would be best. This plant can handle soft to moderately hard water (3 – 8 dGH). Luckily, Betta fish require the same conditions, so if you already have a cycled Betta tank, you can add a Java fern at any time.


The best way of planting a Java Fern in a Betta Tank and most tanks, is to attach its roots to a piece of driftwood or rocks. With roots buried in the substrate like sand or gravel, the plant will grow extremely slow, or even die off. As this plant uses its roots to absorb nutrients, burying them is not a great idea at all.

You can tie the roots to the rock or wood with a piece of thread, fishing wire, rubber bands or zip ties. Thread is also a good choice, as it will dissolve over time and leave the roots fixed around the surface. Rubber bands and zip ties can also be used. You can remove them after the roots are well attached.

In a few weeks your Microsorum will start growing.Although usually not necessary you may add fertilizers for extra nutrients,

In their natural environment, Java ferns live attached to rocks, wood or substrate, submerged or partially submerged. If your Betta tanks is uncovered, you can allow some leaves to grow out of it.

Java fern problems

Although a very hardy plant that thrives in many conditions, the Java fern can also suffer from lack of nutrients.

Normally, the plant should start growing after a few weeks or months upon placing it in your Betta tank. If you see no growth whatsoever, you may want to use a bit of liquid fertilizer as per the producer’s directions. Choose one that contains iron, which keeps the leaves green. When lacking iron, the leaves will fade in color, eventually turning black.

While black spots are a sign of lack of nitrogen, black bumps and brown blotches indicate spores that may grow into new sprouts.

Java fern leaves may eventually melt (turn brown and mushy) due to low nutrient levels, excessive growth g blue-green algae or too much light.

The best plant set-up for a Betta tank

Java fern is an amazing plant for Betta fish, as it offers plenty of places to hide and feel more secure. It also provides beneficial bacteria and can absorb some of the ammonia in the water, especially when water parameters are the best.

Although they will not actually eat them, Bettas will nibble on Java fern’s leaves from time to time, usually while grazing for bacteria deposits. Don’t worry, as they won’t harm the plant, and will also benefit from a small amount of vegetable matter. Fibers are great for digestion, even for fish!

With its wide leaves and large size, the Java fern should be placed in the midground area of your Betta tank. Placing it in the foreground will hide all the aquarium set-up away. Java fern will spread by itself, so only add it in one corner or small area in your Betta tank, so you don’t take away a lot of swimming space.

Plants are a great way of making your Betta tank more appealing to fish and viewers as well. They also provide safe places to hide from predators, as well as safe nesting places for females to lay their eggs.

Does Java fern help clean water?

Given its slow growth rate, it won’t absorb many of the nutrients in your Betta tank.

It harbors many beneficial bacteria, though, which consume ammonia, nitrates and nitrites greatly improving water quality.

Java fern care guide FAQ

Is this plant suitable for beginners?

Yes, it is very easy to care for and doesn’t need special conditions.

Is Java fern a good tankmate for my Betta fish?

Java fern is very friendly, making a great place for fish to hide in. It is also non-toxic, in case they tend to eat it.

Is it best to plant the Java fern in the substrate or attach it?

Java ferns use their roots to absorb nutrients, so planting them in sand or gravel can kill them. It is best to attach it to wood or rock, or let it float until it attaches to something by itself.
It is best to offer it a rough surface to attach to. Smoother surfaces can make this process longer.

How long can Java fern live without light?

This is a hardy plant that can live up to one week without light. Even if they prefer low light and brackish water, Java ferns will eventually wilt if kept in the darkness for too long. On the other hand, if kept under too much or too bright light, the plant’s leaves may burn, turning brown or transparent.

Does Java fern need to be submerged?

Java fern will tolerate many living conditions, so you don’t need to keep it submerged at all times. In its natural environment, it will live in any conditions: fully submerged, immersed, or out of the water. This plant prefers high humidity, so make sure its roots are always in contact with water.

Why do my Java fern’s leaves turn brown?

There may be lots of reasons for this: high or strong light, poor water conditions, lack of nutrients, old age, or the plant might simply not be acclimated to your tank yet.
Brown leaves in newly added Java ferns can be normal until a certain point. However, in established plants, this might indicate a problem in your tank


If you are looking for a beautiful plant that also helps keep the water in your Betta tank healthy, Java fern is a great addition. Java fern is very easy to care for. Bettas love swimming through its leaves and hiding in them.

If you want to learn more about Betta’s behavior, advice, and tips, please visit our collection of Betta Tips Articles.

If you want to read more articles about plants, please visit our posts here.

About the author

Hi, I am Laura. I love fish and pets in general.
I have researched aquariums extensively. I have worked in pet stores, helping customers do the right choices. I am also the owner of two cats.

You can find the articles I wrote here

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