Marimo Moss Ball (Aegagropila linnaei) Care Guide

A unique spherical algae colony that naturally forms a velvety green ball. Requires almost no care and can live for decades, making it a charming low-maintenance addition to any tank.

Overview

Aegagropila linnaei is an aquatic plant in the family Cladophoraceae. A unique spherical algae colony that naturally forms a velvety green ball. Requires almost no care and can live for decades, making it a charming low-maintenance addition to any tank.

Taxonomy

Family: Cladophoraceae
Genus: Aegagropila
Scientific name: Aegagropila linnaei
Other names: Marimo, Lake Ball

Habitat

A rare growth form of the filamentous green alga Aegagropila linnaei, found in lakes in Japan (Lake Akan), Iceland (Lake Mývatn), Estonia and Scotland. The spherical shape develops through gentle wave action that rolls the colony on the lake floor. Protected as a Special Natural Monument in Japan since 1921.

Growth requirements

Light: low (≈30-50 PAR at substrate)
CO2: optional (CO2 improves growth and coloration)
Temperature: 18-25 °C
pH: 6-8
GH: 3-15 °dGH
Substrate: any (rootless or floating)
Nutrient demand: low
Growth rate: slow
Difficulty: beginner

Placement

Recommended placement: foreground
Maximum height: 12 cm

Propagation

In cultivation the plant is propagated by vegetative division or fragmentation.