Hornwort (Ceratophyllum demersum) Care Guide
A fast-growing floating stem plant with fine needle-like leaves that absorbs excess nutrients rapidly. Excellent natural water purifier that helps control algae in new and established tanks.
Overview
Ceratophyllum demersum is an aquatic plant in the family Ceratophyllaceae. A fast-growing floating stem plant with fine needle-like leaves that absorbs excess nutrients rapidly. Excellent natural water purifier that helps control algae in new and established tanks.
Taxonomy
- Family: Ceratophyllaceae
- Genus: Ceratophyllum
- Scientific name: Ceratophyllum demersum
- Other names: Coontail
Habitat
Has a cosmopolitan distribution, native to every continent except Antarctica. Free-floating, rootless plant; stems carry whorls of 6-12 stiff, brittle forked leaves and form turions that overwinter on the bottom. Allelopathic toward phytoplankton and cyanobacteria.
Growth requirements
- Light: low (≈30-50 PAR at substrate)
- CO2: optional (CO2 improves growth and coloration)
- Temperature: 15-30 °C
- pH: 6-8
- GH: 3-18 °dGH
- Substrate: any (rootless or floating)
- Nutrient demand: low
- Growth rate: fast
- Difficulty: beginner
Placement
- Recommended placement: floating at the surface
- Maximum height: 60 cm
- Trim every: 7 days
Propagation
In cultivation the plant is propagated by stem cuttings (replant the upper portion after trimming).