Killer Algae care guide
Killer Algae (Caulerpa taxifolia) — medium light, 18-28 °C, pH 8-8.4, no CO2.
Compiled by Aquairi from published sources · Published · Updated
Overview
Killer Algae (Caulerpa taxifolia) is an aquatic plant of the family Caulerpaceae, listed in the Aquairi knowledge base as an intermediate-level species. It is typically grown under medium light and without obligatory CO2 injection on fine sand. Feather-like macroalgae used in some refugiums; aggressive grower. STRICTLY restricted/illegal in many countries due to extreme invasiveness in temperate seas — verify legality before keeping.
Taxonomy
- Family: Caulerpaceae
- Genus: Caulerpa
- Scientific name: Caulerpa taxifolia
- Common synonyms: Mediterranean Caulerpa
Habitat
Caulerpa is a genus of green marine macroalgae (Caulerpaceae) of warm seas worldwide; the entire alga is a single giant cell, with a creeping stolon, holdfast rhizoids and upright fronds. In the Aquairi knowledge base, populations associated with this form are recorded from Cosmopolitan.
Growth requirements
- Lighting: medium
- CO2: not required
- Temperature: 18-28 °C (64-82 °F)
- pH: 8-8.4
- GH: 8-12 °dGH
- Substrate: sand
- Maximum height: 25 cm
- Growth rate: fast
- Recommended placement: midground
Placement
Grown in a refugium or display, anchored among live rock; bright light and stable salinity drive growth and nutrient export from the system. In the Aquairi knowledge base this form is recommended for the midground under medium light and without obligatory CO2 injection, using fine sand.
Propagation
Spreads vegetatively along the stolon and from fragments; trimming runners and removing detached pieces controls its spread. Documented propagation techniques for this entry include: horizontal runners.
Common issues
Under stress or long darkness it can undergo a sudden reproductive event (going sexual), releasing gametes and crashing while clouding the water; regular harvest and a reverse-daylight refugium reduce the risk.
Caulerpa taxifolia: Killer Algae — Propagation and Legal Warning
Overview
Caulerpa taxifolia is a light-green marine macroalga with stolons on the sea floor from which sparsely branched, feather-like upright fronds of roughly 20-60 cm arise. Despite its plant-like look, it consists of a single cell with many nuclei and has been identified as the largest known single-celled organism. It produces a defensive compound, caulerpenyne. An aquarium strain, a cold-resistant clone, was developed and distributed to public aquariums.
Propagation Method
Where legal, it propagates purely by fragmentation of the stolon. The aquarium strain shows reduced sexual reproduction, but fragments as small as 1 cm are capable of producing viable plants, which is exactly why it spreads so destructively. Division of the runner, not substrate cuttings, is the mechanism. This same trait is the core invasion hazard.
Step-by-Step
- First confirm the species is legal to keep in your jurisdiction; if in doubt, do not propagate.
- Work over a container so no fragment escapes; treat every cut piece as a potential invader.
- With clean scissors divide the stolon into segments, each with a frond and rhizoids.
- Anchor segments against rock so the rhizoids grip; keep flow gentle at first.
- Bag and bin any offcuts; disinfect tools and never rinse them into a drain.
Conditions for Healthy Growth
It tolerates a wide range, roughly 18-28 °C, pH about 8.0-8.4, and moderate light, and is an aggressive grower — that cold tolerance is what let the strain colonise temperate seas. Sediment-rich sand suits the rhizoids, which take up nutrients from the substrate.
Maintenance
Harvest frequently to export nutrients and control the aggressive spread. Capture every offcut; never let trimmings drift to an overflow or sump outlet. All removed material goes into a sealed bag and then the trash.