Reading Progress
Marimo as Biofilters: Studies That Prove They Clean Water

Marimo as Biofilters: Studies That Prove They Clean Water

June
16,
2025
|
Brian Barcenilla
|
4 min read

Marimo look simple, but they play a powerful role in fresh water. As biofilters, Marimo soak up pollutants like nitrates, phosphates, and ammonia, making them a sustainable choice for water purification. 

You might be wondering, “Do moss balls help filter water?” or “Do Marimo moss balls filter water?” Well, you’re in luck! This post rounds up solid studies from trusted sources to show how Marimo tackle water cleanup with their unique algal-bacterial structure. 

Let’s explore the science behind these fascinating green balls and their role in keeping water crystal clear.

Marimo in Wastewater Treatment

A ScienceDirect study highlights Marimo as biofilters in municipal wastewater treatment, and the results are impressive. Researchers compared Marimo to lab-grown microalgal-bacterial granular sludge (MBGS) in outdoor tests. 

Marimo’s dense, ball-like structure traps pollutants, clearing organic matter and nutrients like ammonia and nitrates. Over time, it matched MBGS performance, showing it’s a top pick for eco-friendly water treatment. Here’s what makes Marimo great:

  • Microbial teamwork: Their bacteria buddies break down pollutants, boosting decontamination.
  • Durable design: The compact form holds up in tough conditions without breaking apart.
  • Low upkeep: Marimo’s slow growth means less hassle for long-term use. This study also notes Marimo’s ability to handle high pollutant loads, making them ideal for large-scale wastewater systems where sustainability is key. 
Marimo in Wastewater Treatment

Photo by Science Direct

Marimo’s Buoyancy and Biofiltration

A Journal of Biological Engineering study explores Marimo’s photosynthetic powers, where they produce oxygen bubbles that adjust their buoyancy. While it focuses on Marimo as actuators (like tiny biological machines), it also sheds light on their biofiltration skills. 

Their microbial communities gobble up pollutants, confirming that Marimo moss balls help purify water by tackling organic waste. 

The study points out how Marimo’s photosynthetic filaments act like a natural cleaning crew, breaking down harmful substances in water environments. This makes them a versatile tool for both science and sustainability.

Microbial Ecology and Biofiltration

An MDPI review gets into the microbial world of biofiltration, and Marimo are right at home. It covers bacteria like sulfur-oxidizers that likely help Marimo filter out compounds like hydrogen sulfide. 

This confirms that moss balls help clean water, though they’re not a complete replacement for heavy-duty filtration systems. What’s cool? Marimo’s slow growth keeps maintenance low, and their natural carbon fixation helps balance water chemistry. 

The study also suggests Marimo could work in tandem with other biofiltration techniques, making them a practical choice for sustainable water cleanup projects in various settings.

Wrapping Up

Marimo as biofilters are a natural, sustainable solution for cleaner water. From wastewater treatment to small-scale purification, these green balls shine with their algal-bacterial teamwork. 

The studies linked here, straight from Google Scholar and trusted sources, prove Marimo are legit for water cleanup. From scientific interest to practical application, Marimo offer a low-maintenance, eco-friendly way to remove pollutants and keep water crystal clear.

More internal studies:

Want to learn more tips, fun facts, or how to care for your own Marimo in a jar? Visit Moss Amigos for everything you need to get started.

Moss Amigos

Photo by Sravya D., Moss Amigos internship

Frequently Asked Questions

Do Marimo Moss Balls Purify Water When Kept in Jars?

Yes, Marimo in jars naturally absorb pollutants, Their algal-bacterial makeup helps maintain cleaner, clearer water without chemicals or electricity, making them ideal for low-maintenance water care.

How Often Should I Change the Water in a Marimo Moss Ball Jar?

Change the water every 1–2 weeks to keep conditions optimal. Marimo help filter the water, but occasional changes ensure freshness, remove buildup, and support the moss ball’s natural purification abilities over time.

Are Marimo Moss Balls a Sustainable Option for Water Purification?

Absolutely. Marimo are slow-growing, long-lasting, and require no power or synthetic materials. Their natural biofiltration process makes them an eco-friendly choice for cleaner water in home or office jar setups.

 

References:

https://www.researchgate.net/publication/272109743_Effect_of_Municipal_Wastewater_Treatment_by_Biological_-_Ecological_Filter_BEF

Phillips, N., Draper, T. C., Mayne, R., & Adamatzky, A. (2019b). Marimo machines: oscillators, biosensors and actuators. Journal of Biological Engineering, 13(1). https://doi.org/10.1186/s13036-019-0200-5

https://www.sciencedirect.com/topics/biochemistry-genetics-and-molecular-biology/sulfur-oxidizer#:~:text=Sulfur%20Oxidizers&text=Reduced%20sulfur%20compounds%20are%20usually,nitrate%20can%20also%20be%20used.

Want to know more?

Join our email list and be the first to know about new limited edition products, material innovations, and lots of other fun updates.
Created using