Water sprite

Quick facts

Max height

40 cm

Growth rate

fast

Difficulty

beginner

Placement

background, floating

Propagation

daughter plants

Water parameters

Temperature

20–30°C

pH

5.5 to 8.0

Hardness

2 to 20 dGH

Light and nutrients

Lighting

low

CO2

not required, but boosts growth and color

Substrate

any

Feeding

feeds from both water column and roots (liquid ferts plus root tabs)

Substrate

What this plant roots into (or attaches to). The substrate affects both plant nutrition and water chemistry; see each linked page for full effects.

This plant feeds primarily from the water column, so substrate choice matters more for its fish-tank compatibility than for plant nutrition.

With fish

Plant-eating fish

will be eaten by mollies, silver dollars, large goldfish, and other plant-grazers

Diggers (corydoras, loaches)

may get uprooted by active diggers

Root-disturbing fish

sensitive to root disturbance, plant where roots stay undisturbed

Habitat

Native to tropical and subtropical regions across Asia, Africa, and the Americas. The species (Ceratopteris thalictroides) is an aquatic fern with finely divided, bright green fronds that grow either rooted in substrate or floating on the surface. The fronds are deeply lobed and lacy, creating a feathery, open texture. Water sprite is one of the fastest-growing aquarium plants and one of the most effective nutrient sponges, pulling nitrate and phosphate from the water at a rate comparable to floating plants. The plant has been a staple of the aquarium hobby for decades, valued for its versatility, fast growth, and use as a natural water purifier in newly cycling and overstocked tanks. The species name 'thalictroides' means resembling Thalictrum (meadow rue), referring to the finely divided frond shape. Water sprite is one of the few truly amphibious aquarium ferns, growing equally well submerged, emergent, or floating. The terrestrial form (C. cornuta) is sometimes sold separately but is the same species in a different growth phase. Widely distributed across tropical latitudes and naturalized in warm regions worldwide.

Care notes

Extremely easy. Grows in any light (moderate to high produces the fastest, most robust growth), any water chemistry (pH 6.0-8.0, soft to hard), temperature 20–30°C, and without CO2. Can be planted in substrate (where it develops a root system and grows upright) or left floating (where it grows larger and more rapidly, with fronds spreading across the surface). Floating water sprite produces adventitious plantlets on the frond margins; small plants form directly on the older fronds and detach naturally, each growing into a new plant. This prolific reproduction means a few sprigs quickly become a tank full. Trim aggressively and discard excess; the plant doubles in mass every 1-2 weeks under good conditions. The fast growth makes it one of the best plants for competing with algae in new tanks. The lacy fronds provide excellent cover for fry and egg-laying fish. Betta keepers often use floating water sprite as a bubble nest anchor. Available from pet stores and hobbyist trades at low cost. A foundational plant for any fishkeeper.

Further reading

• How to cycle a fish tank