Marimo Moss Ball

Marimo Moss Ball

Aegagropila linnaei

Marimo Moss Ball is one of the most distinctive additions to a freshwater aquarium. Despite its common name, Marimo is not actually a moss or a vascular plant—it is a naturally spherical growth form of filamentous green algae, Aegagropila linnaei.

Its soft, velvety texture and naturally rounded shape make it an attractive foreground accent, especially in minimalist aquascapes, nano tanks and shrimp setups. Marimo grows extremely slowly and requires very little maintenance compared with most aquarium plants.

Plant Profile

• Scientific Name: Aegagropila linnaei

• Common Name: Marimo Moss Ball

• Type: Filamentous green algae

• Growth Rate: Very slow

• Difficulty: Very easy

• Placement: Foreground / substrate

• Light: Low to moderate

• CO₂: Not required

• Temperature: 18–24°C

• pH: Approximately 6.5–8.0

• Propagation: Division

Marimo generally prefers cooler, stable water and low-intensity lighting. Prolonged exposure to high temperatures or intense light can contribute to browning and deterioration.

Appearance & Growth

Marimo forms a compact, rounded ball covered in extremely fine green filaments. Its spherical shape develops naturally in environments where gentle water movement helps rotate the algae over time. In an aquarium, growth is exceptionally slow, making it useful when you want greenery without frequent trimming.

Care & Maintenance

Marimo does not need to be planted into substrate. Simply place it on the aquarium floor where it can receive gentle water movement.

Occasionally turning or rotating the ball helps expose different sides to light and helps maintain a more even shape. It can also be gently rinsed or rolled in clean aquarium water when debris accumulates.

Avoid strong direct lighting and excessive heat. For tropical aquariums maintained at higher temperatures, Marimo may not be an ideal long-term choice because it naturally favors cooler conditions.

Ideal For

Marimo Moss Ball works particularly well in:

• Shrimp aquariums

• Nano aquariums

• Low-tech setups

• Minimalist aquascapes

• Natural-style aquariums

• Foreground compositions

Its dense surface can also provide a useful grazing area for shrimp and other small aquarium inhabitants.