TankBud

Phoenix moss

Fissidens fontanus

Also known as Fissidens, US Fissidens, Octodiceras fontanum

FreshwaterMossDivisionFragmentation

Phoenix moss (Fissidens fontanus)
Aquarium Plants Factory · Used with permission

Care at a glance

Light
Medium light
CO2
CO₂ beneficial
Temperature
68–82°F
20–28°C
Max height
2 in
5 cm
Growth rate
Slow
Placement
Epiphyte
Type
Moss
pH
6.0–7.5
Hardness
2–15 dGH
Spread
3.9 in (10 cm)
Nutrient uptake
Water column
Growth region
Submersed
Difficulty
Medium
Family
Fissidentaceae
Origin
North America (widespread in the United States), submersed on wood and rock in rivers, streams, and ponds

Overview

Phoenix moss is a slow-growing moss with a fine, feathery look, used as a carpet or as an accent on hardscape. It is rated medium in difficulty.

Did you know

Phoenix moss spends its whole life underwater. Unlike many aquarium mosses it is not a bog plant, and it is one of relatively few mosses adapted to permanent submersion.

Caring for phoenix moss

Tie or glue thin pieces of phoenix moss onto wood or stone. Thick wads trap debris and brown out underneath. The moss grips well once it is established.

Phoenix moss responds to light and CO2 more than easier mosses do. Medium light with added CO2 gives compact, well-defined fronds, while a low-tech tank grows it loosely and even more slowly. It feeds from the water, so dose a liquid fertilizer and keep it at 68 to 82°F (20 to 28°C).

Expect a few months before a tied piece spreads into real coverage. To make more, pull a clump apart into smaller pieces and tie each one down. Pieces that break off keep growing too.

Good to know

Phoenix moss, Fissidens fontanus, is a true moss in the family Fissidentaceae, and it was historically also placed in the genus Octodiceras. Each leaf has an unusual sheathing base that wraps the stem. The leaves sit in two flat ranks, which gives each frond its fern-like look. It reached the hobby fairly late and is still sometimes sold as US Fissidens, to set it apart from imported Asian Fissidens.

In the wild

Phoenix moss is native to North America and widespread across the United States. It is one of the few aquarium mosses that does not come from tropical Asia. It grows submersed on wood, rock and other surfaces in rivers, streams and ponds, where it forms low, dense mats of overlapping feathery fronds.

Common questions

Does phoenix moss need to be planted in the substrate?

No. Phoenix moss grows on rock or wood rather than in the substrate. Tie it on with cotton thread or fishing line, or use gel superglue, until it anchors itself.

Does phoenix moss need CO2?

No, but it helps. Phoenix moss can grow without injected CO2, and added CO2 makes it grow faster.

How much light does phoenix moss need?

Phoenix moss wants medium light. A light sold for planted tanks covers it.

How do you propagate phoenix moss?

Phoenix moss propagates by division and fragmentation. Pull a clump apart into smaller pieces and tie each one down. Pieces that break off keep growing, so pulling a clump apart spreads it.

How tall does phoenix moss grow?

Phoenix moss grows to about 2 in (5 cm) tall. It grows slowly.

Related plants