How To Make A Marimo Moss Ball (& Care For Yours)

Marimo, also known as Cladophora ball, moss ball, and lake ball, is an uncommon growth form of Aegagropila linnaei (a kind of filamentous green algae) in which the algae form huge green velvet-like balls. You can find this species in a variety of water bodies like rivers and lakes in Japan and Europe.

The name “Marimo” was given by a Japanese botanist named Tatsuhiko Kawakami in 1898. However, the term is slightly misleading, as ‘mari’ means ball, and ‘mo’ indicates algae in Japanese. Even though they are actually produced from strings of algae rolled into a ball, due to the negative connotations of the term “algae,” these balls are more commonly referred to as moss.

Moss balls are perfect additions to liven your aquariums and terrariums. Read on, and you’ll have your own moss balls in no time!

Can You Make Your Own Moss Ball?

One of our favorite new plant finds in recent years is moss balls. Strange and lovely best describes moss balls. In addition, they require little maintenance. They’ve recently gained popularity for use in both freshwater aquariums and ponds for aesthetic purposes.

Moss balls are, without a doubt, the easiest of their kind to make and maintain. Really, it’s the kind that you can just set up and forget about. The only things you need are some water and a fluffy moss (technically algae). Putting them together is a bit messy but well worth the trouble.

How Are Moss Balls Made?

Marimo moss balls were first discovered in cold, freshwater lakes like Japan’s Lake Akan and Iceland’s Lake Myvatn. Making your own moss balls is not new, and there are many different ways to do it. The best thing about moss balls is that they don’t have to stay round. Aegagropila linnaei grows in nature as flat mats on rock surfaces, free-floating filaments, and shaggy sheets on the bottom of lakes.

This has led aquascapers to get quite inventive with moss balls, unrolling them into thick carpets, draping them on hardscape, and even flattening them to construct underwater bonsai trees. Others store their marimo balls in elegant jars as house decor rather than in fish tanks. You won’t find anything easier to care for than this attractive algae, making it perfect as a low-maintenance moss ball or a fun addition to your fish tank. People who keep fish in aquariums use them to naturally clean the water, and they don’t mind living with other water plants either.

How Do You Make An Aquarium Moss Ball?

Moss balls, which are also called Marimo balls, are a popular type of Japanese aquatic plant. Not only are these balls of moss pretty to look at, but they also do a lot of important things in an aquarium. Moss balls help clean the water by filtering out dirt and other things that shouldn’t be there, and they give smaller fish a safe place to hide. Moss balls also help control the amount of oxygen in the water and can even take in extra nutrients from the water.

Here’s everything you need to know about making your own moss ball if you want to put one in your aquarium.

Gather All Necessary Materials

You’ll need a piece of string or thread, some aquarium-safe glue, and a handful of live moss. You will also need a good amount of live moss. You can find live moss at most pet stores, or if you’re feeling adventurous, you can collect it from the wild. Once you have everything you need, you can start.

Once You Have the Live Moss, Create a Ball of It

Tie a small loop in the string and glue it to the center of your chosen piece of moss. Then, simply keep adding more moss and squeezing it until the ball is the size you want.

Once the Moss Ball Is Complete, Simply Place It in Your Aquarium

Watch as it slowly unfolds in the water. With a little patience and care, you can create a beautiful addition to your fish tank that will help to keep your water clean and healthy.

The moss will gradually take on a sphere shape as it gathers nutrients from the water. When your moss ball has matured, place it carefully on the gravel or rocks in your aquarium. Keep an eye on your moss ball and add more water as needed; if it dries out, it will start to decompose and clump back together. With TLC, your moss ball will flourish in its new environment and bring you joy for years to come.

japanese marimo mossball green algae in glass of water

How To Re-Roll A Moss Ball

Moss balls, also known as marimo balls, are a type of algae that has been popularized as a low-maintenance pet. These unique little creatures are actually quite easy to care for. They make a beautiful addition to any fish tank. One thing to keep in mind, however, is that moss balls will slowly start to break down over time. When this happens, it’s important to know how to re-roll them so that they can continue to thrive.

  • Gently remove the moss ball from its container. Place them in a container with clean water. Again, make sure it is treated water and not regular tap water.
  • Hold them gently in your hands and swish them lightly in the water a few times. Give it a light squeeze to squish out any dirty water, kind of like a sponge. Keep doing this until it turns vibrant green again.
  • Once you have ensured that the ball is clean, you can begin to roll it between your hands in order to shape it into a compact sphere.
  • Finally, place the ball back in its original container and give it a light press to assist remove any air bubbles that may have formed.

How To Make A Moss Ball Tree

The idea of making a closed ecosystem is interesting to people who like water. They are always eager to make their own miniature aquatic world. This hobby brings the underwater world into your room, making it look more natural, lively, and relaxing.

Marimo balls are good for making an ecosystem because they are easy to take care of and need a cooler temperature away from light. It can be used in many different ways because of how it looks. You can use it to cover the floor of the aquarium, make driftwood trees, or just put these fluffy balls in the aquarium.

Here’s how to create a moss ball tree.


  • Driftwood
  • Slatestone   
  • Marimo Moss Balls          
  • Super Glue  

Choose the Appropriate Type of Wood

Look for pieces of driftwood that have a lot of personality. Choose branches that you can easily put parts together with the help of the superglue to build a realistic miniature tree.

Affixed Miniature Tree on the Stone Slate

Make the little tree attached to the flat stone slate with the help of super glue. Just give it another night to dry.

Add Foliage

Get the marimo moss balls and create the leaves of the miniature tree. You can break them up or reshape the moss balls if necessary to make them as realistic as possible. Dab a little amount of glue to the top of the branches, just enough for the moss balls to stick.

Place the Tree Into the Jar

Gently place the miniature tree inside the fish tank or terrarium. You will be able to build a stunning aquatic ecosphere for your living space if you have a miniature tree made of moss balls!

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How To Care For A Moss Ball

The first moss balls were made in Japan. These small green fuzzy balls are commonly referred to as moss balls and can be seen in fish tanks and aquariums. Most people would think they are made of moss, but that’s not really true. Marimos are actually a type of algae that grows in dim light and, under certain conditions, turns into a round ball.

Moss balls can be kept in fish tanks, aquariums, or as low-maintenance pets. They don’t have many needs when it comes to care or the environment, but there are a few things you should think about to make sure your moss ball stays healthy.


Moss balls work great in aquariums, but you can also keep them in glass bowls, bottles, vases, and other containers. Since they can thrive without oxygen, marimo can be kept in closed environments. You might find that it takes your moss balls one to two days to sink to the bottom of your tank or container.

If it is floating, it’s likely because there are air bubbles inside the balls. You can let the air bubbles out of the moss balls by giving them a gentle squeeze while holding them under water.


Moss balls grow at the bottom of lakes on their own, so they don’t need special or bright lighting. Most of the time, they can get enough light to make food from the light in their homes or from windows. Most aquarium lights and lamps work fine for them. If your moss ball is exposed to too much light, like direct sunlight or bright LED lights, it might get brown spots.

If you leave your moss ball still for a long time, you may need to flip or spin the ball to make sure that all sides get enough light.

Water Changes

It’s important to change the water in your bowl so that dirt and waste don’t build up on it. How much and how often you change the water will depend on the size of the aquarium or container where you keep your moss ball. If you only have the moss ball in the container and no other plants or animals, you should change about half of the water every two weeks or so.

If you keep the moss balls in a tank with animals and other plants, you may need to change the water more often. How often you do this will depend on your situation.


If you don’t keep your moss balls with animals that eat algae, like dwarf shrimp and some types of fish, you may need to clean the moss balls every so often. You can do this by taking your moss balls out of the water and rinsing them, then putting them in a container of clean water and gently squeezing the ball a few times.

While you do this, it’s also a good idea to carefully roll the ball in your hands for a few moments. Since your moss ball is no longer living in a lake where waves move it around, it may change shape over time. Gentle rolling will help the ball get back to its round shape.

Tank Mates

Moss balls can live with most animals in the same tank. But some fish and invertebrates, like Goldfish, some types of Plecostomus (Plecos), and large-sized crayfish, may eat or damage moss balls.


You may make more moss balls by slicing one into smaller parts and then rolling those pieces into new balls. Keep in mind that the marimo ball is a very sluggish grower and may only increase in size by about 5 mm every year. A little fertilizer will help it along, but it won’t suddenly explode in size at any time in its existence.

Moss balls are easy to take care of, but they do require a bit of maintenance in order to stay healthy and look their best. Be sure to follow the tips we shared above, and your moss ball will be thriving in no time.


So, there you have it. Everything you need to know about moss balls! If you’re feeling inspired and want to try your hand at making some of your own, we’ve got a few simple instructions for you below. But be warned – they can be addictive! Once you start making moss balls, you may find yourself wanting to make them in all sorts of shapes and sizes. Thanks for following along with us on this journey into the world of moss balls. We hope you enjoyed it as much as we did. Now get out there and start creating!

About the author

Hey there! I'm Antonio, the passionate owner and chief editor of Betta Care Fish Guide. With over half a decade of hands-on experience, I've become your go-to expert for all things betta and tropical fish.

Over the past 5 years, I've not only kept bettas and other tropical fish but also connected with a diverse network of hobbyists, seasoned fishkeepers, and even veterinarians.

Now, I want to help other beginner fish keepers who had the same questions as me when they were just starting out! So they can save themselves a ton of time and keep their fish happy and healthy!