How much light does Floating Fern need?

Medium light, around 30–60 µmol·m⁻²·s⁻¹ of PAR. Watts are not comparable between fixtures; PAR is. If the manufacturer does not publish PAR, pick one band lower than the tank depth suggests.

Does Floating Fern need CO₂?

No. Marked "not needed": it grows normally in a tank with no CO₂ at all. These are usually slow growers that are also forgiving about light.

What water does Floating Fern want?

18–28 °C, pH 6–7.5, 2–12 dGH. At 10 dGH wide it is one of the more forgiving ranges.

How fast does Floating Fern grow, and where does it go?

Growth rate: fast. Placement: floating. Substrate: no substrate needed. Difficulty: beginner.

G-02 / 22Freshwater

Floating Fern槐叶萍

Salvinia natans · Salviniaceae

Its leaves are hairy and shed water but hate being rained on, and as a temperate species it dies back to resting buds in winter.

Illustration to come

G-02 / 22 · Floating Fern Salvinia natans

SpecificationsPlant atlas

Name: 槐叶萍
Scientific name: Salvinia natans
Family: Salviniaceae
Origin: Still ponds of temperate Eurasia (China, Japan, Europe)
Light: Medium light
PAR: 30–60
CO₂: Not needed
Hardness: 2–12 dGH
Growth: Fast
Placement: Floating
Substrate: No substrate needed
Level: Beginner

Water requirementsFreshwater

Temp.18–28 °C

pH6–7.5

Hardness2–12 dGH

Alkalinity1–8 dKH

Units: temperature in °C, hardness in German degrees (dGH / dKH), marine salinity as specific gravity at 25 °C, volume in litres. These are the values recorded for the species and do not follow the site unit switcher.

Growing notes

1Once the hairy surface is soaked it rarely recovers, so never pour water over it and keep the water level below the leaves.
2It stacks up fast enough to cover half the surface in a week, so thin it regularly.
3Browning usually means water above 30 °C or raised ammonia, and once that settles new leaves come from the rhizome.
4Below 10 °C in autumn and winter the whole plant dies back, leaving only resting buds to overwinter.
5It suits a covered tank, but keep the heat of the light from drying the leaves out.

Frequently asked questions

How much light does Floating Fern need?: Medium light, around 30–60 µmol·m⁻²·s⁻¹ of PAR. Watts are not comparable between fixtures; PAR is. If the manufacturer does not publish PAR, pick one band lower than the tank depth suggests.
Does Floating Fern need CO₂?: No. Marked "not needed": it grows normally in a tank with no CO₂ at all. These are usually slow growers that are also forgiving about light.
What water does Floating Fern want?: 18–28 °C, pH 6–7.5, 2–12 dGH. At 10 dGH wide it is one of the more forgiving ranges.
How fast does Floating Fern grow, and where does it go?: Growth rate: fast. Placement: floating. Substrate: no substrate needed. Difficulty: beginner.