Why do we love Marimo Moss Balls?

We can't get enough of this mesmerising moss balls, and you may be asking, are these really rounded pieces of moss?

Funnily enough, the fact that they are called Marimo moss balls is extremely misleading, as in fact, Marimo is not actually moss but a rare species of algae. This algae grows into green balls with a fluffy and velvety appearance.

They can be found in a number of lakes and rivers in Japan and Northern Europe, especially in Iceland, where they have been known to grow up to 12 inches in diameter!

However, keep in mind that in average they grow 5mm a year so they grow slowly for years and years to come. 

This makes Marimo a fun alternative to the traditional heirloom as it can be enjoyed and passed down to many generations to come!

So then, how do I take care of Marimo?


Change the water once a week or every other week. (You can use filtered water, however tap water will be just fine).


As they live on the river beds or the bottom of lakes, low to medium indirect sunlight will help your Marimo photosynthesise. Avoid direct sunlight and hot spots as it will damage them.


Marimo moss balls do not need any food or fertilisers as they create their own food through photosynthesis.


Why are my Marimo Balls floating on the surface?

This happens when they have air bubbles trapped inside. You can leave them floating and they will naturally sink to the bottom when the bubbles are released, or if you prefer, you can squeeze them very gently to release the air bubbles as shown on the video. 

This will also help remove any dust or dirt trapped inside your Marimo. 

My Marimo Moss Balls are changing colour...

If your Marimo Moss Balls are turning: 

- Brown: They are probably getting dirty. Rinse them and squeeze them to remove any dirt before putting them back into the water.

- Slimy green: Your Marimo might be attacked by another algae. Clean it as best as you can and remove the worst affected areas. Roll your Marimo back into a ball.

- White: If your Marimo is turning white, it means that it is receiving too much light. Move it to a cooler darker spot.

- Black: If your Marimo is turning black, unfortunately it might be dying. It can be caused by not having tackled any of the above symptoms quickly enough. 

How do I keep their spherical shape?

Marimo balls develop their round shapes by naturally rolling across the bed of rivers and lakes. At home, they might start losing its round shape and falling apart, which is absolutely normal. To avoid this from happening, simply roll them very gently in your palms as you clean them. 

Our Favourite Marimo shots

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Marimo Moss Balls | The Perfect Indoor Water Garden | cuemars.com

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