How much light does Vallisneria 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 Vallisneria need CO₂?

It is optional. Marked "optional": with CO₂ it grows faster and tighter, without it still does fine.

What water does Vallisneria want?

20–28 °C, pH 6.5–8, 4–15 dGH. At 11 dGH wide it is one of the more forgiving ranges.

How fast does Vallisneria grow, and where does it go?

Growth rate: fast. Placement: background. Substrate: substrate required, reaching about 30–80 cm. Difficulty: beginner.

G-02 / 20Freshwater

Vallisneria苦草

Vallisneria natans · Hydrocharitaceae

The evergreen background tape grass whose runners spread fast and which tolerates harder, more alkaline water.

Illustration to come

G-02 / 20 · Vallisneria Vallisneria natans

SpecificationsPlant atlas

Name: 苦草
Scientific name: Vallisneria natans
Family: Hydrocharitaceae
Origin: Lakes and shallow rivers of East Asia (China, Japan, Korea)
Light: Medium light
PAR: 30–60
CO₂: Optional
Hardness: 4–15 dGH
Growth: Fast
Placement: Background
Substrate: Substrate required
Height: 30–80 cm
Level: Beginner

Water requirementsFreshwater

Temp.20–28 °C

pH6.5–8

Hardness4–15 dGH

Alkalinity3–10 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

1It spreads by stolons and one plant can throw a dozen in a year, so decide about a root barrier before planting.
2Never cut the leaf tips, because a cut leaf stops growing; remove a whole leaf at the base if it gets too long.
3It likes harder, more alkaline water above 6 dGH, and in very soft water without carbon it melts and pales.
4Iron shortage yellows and clears the new leaves, and a thin substrate stalls growth and shortens the leaves.
5Big plants block flow and light below, so leave five centimetres or more between groups and even more when densely planted.

Frequently asked questions

How much light does Vallisneria 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 Vallisneria need CO₂?: It is optional. Marked "optional": with CO₂ it grows faster and tighter, without it still does fine.
What water does Vallisneria want?: 20–28 °C, pH 6.5–8, 4–15 dGH. At 11 dGH wide it is one of the more forgiving ranges.
How fast does Vallisneria grow, and where does it go?: Growth rate: fast. Placement: background. Substrate: substrate required, reaching about 30–80 cm. Difficulty: beginner.