Chaetomorpha

Chaetomorpha linum

Also known as Chaeto, Spaghetti algae, Chato, Green hair algae

SaltwaterMacroalgaeCuttings

Chaetomorpha (Chaetomorpha linum) — no rights reserved · cc0

Care at a glance

Light: Medium light
CO2: No CO₂ needed
Temperature: 72–81°F; 22–27°C
Max height: 7.9 in; 20 cm

Growth rate: Fast
Placement: Floating
Type: Macroalgae
pH: 8.0–8.4
Spread: 11.8 in (30 cm)
Nutrient uptake: Water column
Growth region: Submersed
Difficulty: Beginner
Family: Cladophoraceae
Origin: Cosmopolitan; found in marine and brackish waters worldwide

Overview

Chaetomorpha, or chaeto, is a wiry green macroalga and the workhorse of nutrient export in reef tanks. It is a beginner's macroalga.

Did you know

Chaetomorpha never sends up reproductive structures the way Caulerpa does, so it has no sudden crash or go-sexual event. A rotating ball just keeps growing, which is a big reason it became the default refugium macroalgae.

Caring for Chaetomorpha

Keep Chaetomorpha loose in a lit refugium or sump. Give it gentle tumbling flow so the whole ball rotates and stays clean.

It wants medium, full-spectrum light and no added CO2. It strips nitrate and phosphate straight from the water column, competing out nuisance algae in the display. Keep it at 72 to 81°F (22 to 27°C) with a pH of 8 to 8.4.

It grows fast. Remove a portion of the mass every week or two, because that harvest is what actually exports the nutrients from the system. Any healthy piece keeps growing on its own, so a cut portion can start a new ball. Its dense tangle also shelters copepods and amphipods that feed the tank.

Good to know

Chaetomorpha linum is a filamentous green alga in the family Cladophoraceae. Its stiff, wiry filaments have a coarse, fishing-line texture that resists being eaten by most tank inhabitants. Hobbyists also call it spaghetti algae.

In the wild

Chaetomorpha is a cosmopolitan green macroalga of coastal marine and brackish waters. It forms free-floating tangled masses rather than attaching to a surface, and it tolerates a wide range of conditions.