How much light does Roundleaf Rotala need?

High light, around 60–100 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 Roundleaf Rotala need CO₂?

It is recommended. Marked "recommended": it survives without, but visibly stalls, lengthens between nodes and loses colour.

What water does Roundleaf Rotala want?

20–28 °C, pH 5.5–7.5, 2–12 dGH. At 10 dGH wide it is one of the more forgiving ranges.

How fast does Roundleaf Rotala grow, and where does it go?

Growth rate: fast. Placement: midground / background. Substrate: substrate required, reaching about 20–50 cm. Difficulty: beginner.

G-02 / 12Freshwater

Roundleaf Rotala大血心兰

Rotala rotundifolia · Lythraceae

The easiest stem plant to turn red, though it stays green all over under weak light or high nitrate.

Illustration to come

G-02 / 12 · Roundleaf Rotala Rotala rotundifolia

SpecificationsPlant atlas

Name: 大血心兰
Scientific name: Rotala rotundifolia
Family: Lythraceae
Origin: Paddy fields and wetlands of South and East Asia (India, southern China, Japan)
Light: High light
PAR: 60–100
CO₂: Recommended
Hardness: 2–12 dGH
Growth: Fast
Placement: Midground / Background
Substrate: Substrate required
Height: 20–50 cm
Level: Beginner

Water requirementsFreshwater

Temp.20–28 °C

pH5.5–7.5

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

1Red tops depend on light intensity and nitrate level; weak light and high nitrate keep the whole plant green.
2Trim the top third every week and push the three to five centimetre cuttings into the substrate; never cut a whole clump down at once.
3Planting one stem every centimetre or two prevents bare lower stems, or simply replant the tops from time to time.
4Iron shortage pales and yellows the new growth and dulls the red, and iron plus CO2 restores it within a week or two.
5Mainland shops usually sell it simply as xuexinlan, so buy by the scientific name Rotala rotundifolia and do not confuse it with the amaranth genus Alternanthera.

Frequently asked questions

How much light does Roundleaf Rotala need?: High light, around 60–100 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 Roundleaf Rotala need CO₂?: It is recommended. Marked "recommended": it survives without, but visibly stalls, lengthens between nodes and loses colour.
What water does Roundleaf Rotala want?: 20–28 °C, pH 5.5–7.5, 2–12 dGH. At 10 dGH wide it is one of the more forgiving ranges.
How fast does Roundleaf Rotala grow, and where does it go?: Growth rate: fast. Placement: midground / background. Substrate: substrate required, reaching about 20–50 cm. Difficulty: beginner.