Floating Crystalwort care guide
Floating Crystalwort (Riccia fluitans 'Floating') — medium light, 18-28 °C, pH 6-8, no CO2.
Compiled by Aquairi from published sources · Published · Updated
Overview
Floating Crystalwort (Riccia fluitans 'Floating') is a broad-leaved plant of the family Ricciaceae, grown as an aquarium plant. Bright green liverwort that traditionally floats in dense mats at the surface. Excellent for fry shelter and as a nutrient sponge; can be tied to stones for a 'pearling' carpet under high light and CO2.
Taxonomy
- Family: Ricciaceae
- Genus: Riccia
- Scientific name: Riccia fluitans 'Floating'
- Common synonyms: Riccia
Habitat
Riccia fluitans 'Floating' originates from cosmopolitan wetlands, where it grows in freshwater marshes, ditches and slow-moving streams, frequently emersed on seasonally flooded ground.
Growth requirements
- Lighting: medium
- CO2: not required
- Temperature: 18-28 °C (64-82 °F)
- pH: 6-8
- GH: 2-14 °dGH
- Substrate: any
- Maximum height: 5 cm
- Growth rate: fast
- Nutrient demand: low
- Recommended placement: floating
- Typical trim interval: 14 days
Placement
In aquascapes this plant floats at the surface.
Propagation
Propagation is by stem cuttings replanted into the substrate; daughter plants are separated once they have formed several leaves and visible roots.
Common issues
Pale or stunted new growth usually signals a nutrient or iron deficiency, while algae on older leaves often follows light that exceeds the available nutrients or CO2; correcting fertilisation and trimming affected parts resolves most cases.
Propagating Riccia fluitans 'Floating' (Crystalwort)
Overview
Riccia fluitans is a bright green liverwort that normally grows quickly at the surface and forms thick mats on and under the water. It has no roots or true leaves, just a branching thallus, so it is naturally a floating plant whose name literally means 'floating'.
Any single branch or antler-like bud can reproduce into a large colony in proper conditions, which makes propagation simply a matter of splitting an existing mass and giving the fragments room and light.
Propagation Method
Propagate by splitting the clump into pieces. Each fragment continues growing on its own, so pulling apart a healthy mat instantly multiplies your stock. Fragments left to drift will spread across the surface; pieces pressed under plastic mesh can be grown as an attached carpet.
Step-by-Step
- Scoop out a healthy portion of the floating mass.
- Pull or cut it into several smaller pieces.
- To keep it floating, simply release the pieces at the surface.
- To anchor it, spread a thin layer over a stone and cover with plastic mesh.
- Tie the mesh down and place it under bright light.
Conditions for Healthy Growth
Riccia develops dense, bright green mats positioned a few inches below bright light or in full sun. Under strong light and CO2 the thallus releases visible oxygen bubbles, the prized 'pearling' effect, while the floating mat also shelters fry and absorbs excess nutrients.
- Light: bright; keep it close to the surface or strongly lit.
- CO2: not required to grow, but drives pearling in a tied carpet.
- Use: a retreat for young fry and a nutrient sponge.
- Anchoring: optional, always via mesh rather than roots.
Trimming & Maintenance
Thin floating mats regularly so light still reaches the layers below and lower fish are not left in shade. Skim off excess growth at water changes and re-tie any carpet that has grown too thick before it detaches and floats away.
Common Challenges
Riccia is easily crowded out: duckweed can blanket the surface and shade it, and hair algae readily overtakes it. Keep competing floaters in check and remove algae promptly so the colony keeps spreading.