Water Sprite
Ceratopteris thalictroides
Also sold as Watersprite · Indian water fern
Synonyms Indian fern · Ceratopteris cornuta · Water fern · Ceratopteris siliquosa
Water Sprite (Ceratopteris thalictroides) is a floating plant for the surface and the background, growing to about 40 cm (15.7 in) at a fast pace. It wants 68–82°F (20–28°C), low light and no CO₂, and counts as an easy plant to keep alive.
At a glance
| Type | Floating plant |
|---|---|
| Light | LowThe least light it survives in, not the light it looks best in. |
| CO₂ | Not neededWhether it survives without added CO₂ — not whether CO₂ would help it grow faster. |
| Difficulty | Easy |
| Temperature | 68–82°F (20–28°C) |
| Max height | 40 cm (15.7 in)Grown submersed, left to mature, never trimmed. |
| Growth rate | Fast |
| Placement | floating and planted in the background |
| pH | 6–7.5 |
Before it goes in
- Water Sprite lives under a plain low-light LED — it does not need a planted-tank lamp to survive.
- It grows without CO₂.
- It can be left floating and planted in the substrate.
- At about 40 cm (15.7 in) it belongs behind everything shorter — planted at the front it hides the rest of the scape and shades it.
- Its leaves are medium: Goldfish, Electric Yellow Lab and Colombian Ramshorn Snail will eat it.
Can it grow without CO₂?
Yes. Water Sprite does not need CO₂ at all.
How much light does it need?
Low light is enough — and that is the survival line, not the “it looks better” line.
How big does it get?
About 40 cm (15.7 in) tall when it is mature and untrimmed, growing fast, after roughly 1 weeks to root in.
Will my fish eat it?
Its leaves are medium, so some will: Goldfish, Electric Yellow Lab and Colombian Ramshorn Snail.
What it goes with
- Plants that run on the same light and CO₂, so they can share a tank without one of them being the odd one out: Hygrophila corymbosa 'Siamensis', Anubias nana 'Petite', Cryptocoryne wendtii and Hygrophila corymbosa 'Compact'.
- Animals that share its temperature range and will not eat or uproot it: Betta, Cherry Shrimp, Angelfish and Bristlenose Pleco.
Often compared with
| Water Sprite | Dwarf Water Lettuce | Frogbit | |
|---|---|---|---|
| Light | Low | Medium | Low |
| CO₂ | Not needed | Not needed | Not needed |
| Max height | 40 cm | 10 cm | 5 cm |
| Difficulty | Easy | Easy | Easy |
More plants
Sources (1)
- Max height, Difficultytropica.comSep 2026