Care Guide

Marimo Balls, Moss Balls

Cladophora Aegagropila

Beginner difficulty

Care at a Glance

Lighting

Low

Growth Rate

Slow

Growth Form

Ball

Placement

Foreground or accents

True Aquatic

Yes

Available As

Individual balls

About This Plant

Aegagropila linnaei is actually a well-behaved form of algae!!! It is slowly formed into a ball over a long period of time, by water movement. Originating in very cold rivers and lakes throughout Northern Europe and Japan these Marimo Balls or Moss Balls as they are more commonly, if erroneously, called take long periods of time to form. Aegagropila linnaei will not cause unwanted algae to form in your tank. In fact, Marimo Balls will help prevent nuisance algae by taking nutrients out of the water. "Moss Balls" are a different type of algae than the problem algae that normally forms in aquariums and they are very slow growing. Aegagropila linnaei comes in a range of sizes with the small size in the 3-4 cm range and the XL size in the 10 cm range. Marimo Balls are very easy to decorate with and use for aquascaping. They can be used whole or cut into pieces for creative use in your aquascape. For quite some time, "Marimo Balls" were sold under the name, Cladophora aegagropila.

About the Cladophora Genus

Family — Cladophoracea

Cladophora aegagropila — "Marimo" — is a non-invasive freshwater algae that slowly forms green spheres in cold lakes. They are pet-like, long-lived, and useful for shrimp and snail tanks as biofilm anchors.

Quick-Reference Details

Common name: Marimo Balls, Moss Balls
Scientific name: Cladophora Aegagropila
Family: Cladophoracea
Native to: Europe and Japan
Difficulty: Beginner
Requirements: Easy beginner plant
Lighting: Low
Growth rate: Slow
Growth form: Ball
Placement: Foreground or accents
True aquatic: Yes
Available as: Individual balls

Difficulty — Beginner

Tolerates a wide range of conditions and forgives setup mistakes. Thrives even in low-light tanks.

CO2 & Fertilization

CO2 is not required. This plant performs well in low-tech tanks with only basic liquid fertilization.

Tank Size & Setup

Suits tanks of any size. Foreground carpeting plants work especially well in 10-40 gallon planted setups where the viewer is close to the substrate.

Aquascaping & Placement

Use as a foreground carpeting plant. Plant small portions on 2-3 cm centers and let runners fill the gaps over 4-8 weeks.

Tank-Mate Compatibility

Compatible with the full range of community-tank species — tetras, rasboras, livebearers, corydoras, and most other peaceful freshwater fish do not damage the foliage. Tough enough for cichlid tanks and goldfish setups where most other plants are uprooted or eaten — the leaves are too leathery for those fish to chew through. Excellent in shrimp tanks. The fine leaf structure and biofilm surface make it a top pick for breeding Neocaridina and Caridina species.

Pro Tips for Growing Marimo Balls, Moss Balls

1Roll the moss ball gently every few days to keep its spherical shape.
2Marimo prefers cool water under 75°F (24°C); above that they brown out.
3Periodically swap their water position so all sides get light, preventing brown spots.

Common Care Issues

Pale or stretched leaves

If new growth comes in pale yellow or the stems stretch unusually long, the plant is reaching for more light. Either raise the fixture's intensity or add a richer fertilizer.

Algae on old leaves

Slow growers accumulate dust and spot algae on older leaves. Wipe affected leaves with your fingers during water changes, and consider adding a few Amano shrimp or Otocinclus as cleaners.

Frequently Asked Questions

How much light does Marimo Balls, Moss Balls need?

Marimo Balls, Moss Balls (Cladophora Aegagropila) prefers low lighting. Standard tank lighting is sufficient — no specialty fixture is required.

Does Marimo Balls, Moss Balls need CO2?