Floating Crystalwort

Riccia fluitans

free-floating spawning plant nano tank surface

Other scientific names:Fysonia tenera, Marsilea terrestris, Riccardia dichotoma, Riccia canaliculata fluitans, Riccia centrifuga, Riccia eudichotoma fluitans

A rootless liverwort that grows as a tangle of forking green threads. Traditionally kept floating, it became an aquascaping staple once aquarists learned to tie it down and grow it as a bright, bubbling underwater cushion.

Light: medium
Difficulty: medium
Height: 3 – 5 cm
Temperature: 4 – 30 °C

Leaf colourgreen

Plant typefree-floating

Growth ratefast

CO₂ demandmedium

Tolerates lightmedium – high

pH5 – 7

Carbonate hardness0 – 21 °dKH

General hardness0 – 30 °dGH

Placementspawning plant, nano tank +1

Propagationfragmentation, division +1

Grows emersedyes

Appearance

Flattened, repeatedly forking branches build mats 3 to 5 cm thick and a vivid light green. There are no roots and no stem: every fragment is a whole plant.

Keeping

Kept under water it needs good light and added carbon dioxide, and rewards both by trapping oxygen bubbles on the tips. Growth is fast, and the mat has to be trimmed: new shoots always turn upwards, and an untended cushion tears loose and floats away.

Placement

Tied to stone or mesh it makes a low green cushion; left floating it forms a dense surface mat that is a classic shelter for fry and a spawning site for bubble-nest builders.

Propagation

It falls apart by itself — every piece keeps growing. Divide a mat by hand and tie the pieces down.

Water conditions match

The water suits 861 of 1249 species in the catalogue — these are the ones people look up most often.

Butterflyfish Julii Corydoras Featherfin Synodontis Red-finned Parotocinclus Gastromyzon monticola Egg-shaped Goldfish Flame Tetra Gardner's Killifish African Tetra Hypsolebias picturatus Common Zacco Labeo Bicolor Gambusia Flying barb Gastromyzon scitulus Albino Zebra Danio Geophagus Brokopondo Homaloptera bilineata Red-tailed Rasbora Boraras naevus Lampeye Killifish Spotted Raphael Catfish Corydoras melanotaenia Festivum cichlid

Will eat this plant

These species damage plants, especially when their diet is short of vegetable food.

Bengal Loach Zebra Loach Burmese Border Loach Emperor Botia Marbled Headstander Pellegrin's Leporinus Leporinus striatus False Black Tetra Common Metynnis Mylossoma duriventre Red Whiptail Catfish Moonlight Gourami Melanotaenia parva

The same plant with a different look: light, water and care are shared with the species.

Other varieties: Riccia fluitans Broad