Plant profile

Ceratopteris Siliquosa (Water Sprite)

Ceratopteris thalictroides

Common names: Ceratopteris Siliquosa (Water Sprite), Ceratopteris thalictroides

Background, Floating, MidgroundFast

Send Us A photo, be a contributor :)

Good fit for your tank?

Good fit for

Fast-growing planted or floating cover
Planted aquariums with consistent lighting and fertilising
Shrimp and community aquariums where soft foliage will not be damaged
Keepers willing to trim, replant, and observe new growth

Think carefully if

The aquarium is newly cycled or already struggling with algae
CO₂ or fertiliser delivery is irregular
Frequent trimming and replanting are not practical
The name Ceratopteris siliquosa is treated as a synonym. Water Sprite can be rooted or floated and may produce plantlets on older fronds.

A medium to large aquarium or wetland plant with finely divided fern fronds and light to medium green. Best used for fast-growing planted or floating cover; care and final appearance vary with aquarium conditions.

Growth and Appearance

Usual aquarium appearance

This medium to large plant has finely divided fern fronds. Its commonly observed colour is light to medium green. Colour, leaf size, and internode length can change with light, CO₂, nutrients, temperature, and the individual plant.

It forms fern fronds from a central crown and may grow rooted or floating.

It is normally used for fast-growing planted or floating cover. During the first few weeks, watch the growing tip, roots, and new submerged leaves. Do not judge success only from old nursery-grown foliage.

Requirements

Substrate: Use planted substrate or an inert substrate with root nutrition for rooted species. rootless, floating, and surface growing plants should be positioned according to their growth habit instead of being buried.
Root feeder: Yes
Water-column feeder: Yes

Essentials

Start with low to medium light.
Provide a planted substrate or inert substrate with suitable root nutrition.
Use a complete fertiliser routine that supplies both macronutrients and micronutrients when the aquarium does not provide enough through feeding and livestock waste.
Provide gentle to moderate circulation without repeatedly bending or uprooting delicate stems.
Keep temperature and basic water conditions stable. Observe the plant instead of chasing one exact number.

Optional improvements

Stable injected CO₂ can improve branching, colour, density, and recovery where recommended.
A mature aquarium is easier because early algae and parameter swings are less severe.
Regular topping and replanting can keep stem groups dense and prevent bare lower sections.

Beginner setup checklist

Filtered, cycled freshwater aquarium
Stable light schedule
Suitable substrate or floating position
Consistent fertilising
Gentle circulation around the foliage
Clean scissors and tweezers
Space for the plant’s expected spread or height

CO₂ guidance

Injected CO₂ is optional. It can improve establishment, branching, and recovery, but the plant can usually grow without it when light and nutrients are modest and stable.

CO₂ must remain stable and be balanced with light, macro- and micronutrients, circulation, and oxygen. Adding CO₂ does not make very strong light automatically safe.

Increase light or fertiliser only after the plant is producing healthy new growth. Sudden changes can cause melting, algae, or stalled tops.

Planting and Care

Growth rate: Fast
Growth form: Fern, Floating, Rosette
Rooting type: Floating, Rooted
Propagation: Plantlets, Spores
Emersed growth: Yes

Preparation

Remove the pot and rock wool gently, then rinse the roots.
Remove only fully damaged fronds.

Planting or floating

Plant the roots shallowly while keeping the central crown above the substrate.
Alternatively, float the whole plant with its roots hanging into the water.
Do not bury the crown.

Attachment does not normally apply

This plant should be rooted in substrate, floated, or allowed to spread through runners according to its growth habit. Do not glue healthy stems, crowns, or roots to wood or stone.

Trimming

Use clean scissors to remove a damaged frond at its base.
Do not cut through the central crown.
Remove only part of the healthy foliage at one time.
Plantlets growing on old fronds may be separated after they have several leaves and roots.

Propagation by plantlets and spores

Allow plantlets to develop on mature fronds.
Wait until a plantlet has several leaves and visible roots.
Separate it gently and float it or plant the roots shallowly.
Spore propagation is possible but is less practical for most aquarium keepers.

Propagate only healthy growth. A melting, algae-covered, or recently imported plant should recover before being divided or cut heavily.

Normal adjustment

Transport, planting, and conversion from emersed to submerged growth can cause temporary leaf loss or slow growth.

Normal signs include firm growing tips, new roots, side shoots, and gradual production of new underwater leaves.
Emersed nursery fronds may differ greatly from new submerged fronds.
Colour can change as the plant adapts to the aquarium.

Signs that need attention

Softening stems or crowns, transparent new growth, repeated loss of every growing tip, or spreading decay.
Severe twisting, stunting, or algae appearing mainly after a change in CO₂, light, or fertilising.
Roots repeatedly lifting from the substrate because the plant was planted too shallowly or the flow is too strong.

The name Ceratopteris siliquosa is treated as a synonym. Water Sprite can be rooted or floated and may produce plantlets on older fronds.

Suitability and Problems

Shrimp suitability: Good
Goldfish resistance: Low
Fish damage risk: Moderate
Melt risk: Moderate
Algae susceptibility: Moderate

Common problems

Lower leaves yellow, melt, or fall away: Shading, crowding, adaptation, weak circulation, unstable CO₂, or insufficient nutrition may be involved.
New tips are twisted, pale, or stunted: Unstable CO₂, abrupt environmental change, root damage, or nutrient imbalance can produce similar symptoms.
Plant becomes leggy with long gaps between leaves: Low light, crowding, shading, or delayed trimming may contribute.
Algae or debris collects on leaves: Slow or stalled growth, excessive light, weak circulation, or an imbalance between light, CO₂, and nutrients may be involved.
Freshly planted stems float out of the substrate: Stems may be planted too shallowly, bundled too tightly, or exposed to strong direct flow.

Do not diagnose from appearance alone

Yellowing, holes, pale tips, red colour loss, twisted growth, or slow growth can have several causes. Possible causes include nutrient imbalance, unstable CO₂, unsuitable light, temperature stress, damaged roots, adaptation, algae, or physical damage.

Safe checking order

Review recent water changes, temperature shifts, and equipment changes.
Check whether CO₂, if used, starts consistently and remains stable during the light period.
Compare symptoms on new leaves with symptoms on old leaves.
Inspect roots, lower stems, crowns, and the substrate for damage or decay.
Review fertiliser dosing and whether both macro- and micronutrients are supplied.
Check light intensity and duration rather than assuming more light will fix pale growth.
Change one variable at a time and judge improvement from new growth.

Old damaged leaves will not repair themselves. Use the next several leaves to assess whether the change helped.

Who this plant suits

Beginner tanks: Suitable for beginners when its growth habit and eventual size fit the aquarium.
Shrimp tanks: generally suitable after rinsing and quarantine, with fine foliage providing grazing and shelter.
Low-tech tanks: suitable only when the profile describes CO₂ as unnecessary or optional and the keeper accepts looser, greener growth.
High-tech tanks: useful for stronger colour, compact growth, and faster recovery when the system is stable.
Nano aquariums: suitable only for miniature or frequently trimmed forms.
Community aquariums: suitable with fish that do not uproot or constantly damage plants.

Important limitations

Goldfish and plant-eating fish may uproot, eat, or repeatedly damage the soft growth.
Fast stems need frequent trimming, while slow or delicate forms recover poorly from heavy cuts.
Soft, fine leaves can trap debris or be damaged by rough fish and strong direct flow.
The name Ceratopteris siliquosa is treated as a synonym. Water Sprite can be rooted or floated and may produce plantlets on older fronds.

Plant Decision Guide

Choose it for fast-growing planted or floating cover.
Choose a low-tech setup only when slower, greener, or taller growth is acceptable.
Choose a CO₂-assisted setup when colour, density, or compact form is important and consistent maintenance is possible.
Think carefully if the aquarium is newly cycled, algae-prone, or receives irregular fertilising.
Think carefully if frequent trimming is not practical.
Check local regulations before buying or disposing of plants that can spread from fragments.
Inspect the actual specimen because aquarium trade names and cultivar colours are not always used consistently.

Identification and Origin

Accepted name: Ceratopteris thalictroides
Genus: Ceratopteris
Species epithet: thalictroides
Family: Pteridaceae
Origin: Tropical

Have you grown this plant?

You can write a note about what worked for you, or send a photograph. We check everything before it appears here.

Share a note or photo