Feathered mosquito fern (Azolla pinnata) care guide

Group
Plants
Other names
Mosquito fern, Water velvet, Ferny azolla
Family
Salviniaceae (floating fern family)
Origin
Africa, tropical and eastern Asia, Australia
Water
freshwater
Maximum size
3 cm
Temperature
15–30°C
pH
6–8
Hardness
Tolerant (estimate)
Care level
beginner
Lighting
Medium to high light; CO2 not needed
Flow
Still water; currents break it up

Care

Feathered mosquito fern is a small floating fern from much of Africa, tropical and eastern Asia and Australia, introduced to New Zealand. Its triangular stems are up to 2.5 cm long, covered in overlapping 1–2 mm leaves that are green, blue-green or dark red and velvety with water-repellent hairs. Like other Azolla it carries nitrogen-fixing cyanobacteria and can double its mass in about two days in ideal conditions. It is kept in rice paddies as a natural fertiliser and has been used as poultry feed. It needs quiet water, since currents and waves break it up. In New Zealand it has crowded out the native Azolla rubra and is a waterway pest, and in the United States it is a federal noxious weed. Never release this plant or dispose of it in drains or waterways; it is invasive in some countries. Water figures are our estimate, not from the sources. Sources: Wikipedia (en.wikipedia.org/wiki/Azollapinnata); Wikipedia, List of freshwater aquarium plant species. Checked October 2026.

Breeding

Spreads mainly by fragmentation; also reproduces by spores from sporocarps.

Compatibility and tank mates

Goldfish and many larger fish eat it. Covers the surface quickly, cutting light to plants below and gas exchange for fish, so remove a share every week. Floating plants dislike strong surface flow.

Last updated 8 October 2026. Community-edited care guide on Aquatic-Auctions.

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