How much light does Red Ludwigia need?

High light, around 60–90 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 Red Ludwigia need CO₂?

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

What water does Red Ludwigia 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 Red Ludwigia grow, and where does it go?

Growth rate: fast. Placement: midground / background. Substrate: substrate required, reaching about 20–40 cm. Difficulty: beginner.

G-02 / 13Freshwater

Red Ludwigia红蝴蝶

Ludwigia repens · Onagraceae

The classic red plant with deep red leaf undersides, at its best in cool, low-nitrate water under medium to strong light.

Illustration to come

G-02 / 13 · Red Ludwigia Ludwigia repens

SpecificationsPlant atlas

Name: 红蝴蝶
Scientific name: Ludwigia repens
Family: Onagraceae
Origin: Stream banks and marshes from the southern United States to Mexico
Light: High light
PAR: 60–90
CO₂: Recommended
Hardness: 2–12 dGH
Growth: Fast
Placement: Midground / Background
Substrate: Substrate required
Height: 20–40 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

1The colour comes from anthocyanin and is deepest around 22 °C with low nitrate and eight hours of light a day.
2Under weak light the leaves narrow, the internodes stretch and the clump goes dull green with almost no red.
3It grows fast, so top it and replant every fortnight or the lower leaves drop and leave bare stems.
4Iron or nitrogen shortage yellows the new leaves and potassium shortage holes the old ones; red plants show deficiencies more plainly than green ones.
5The stems snap easily, so hold the lower end with tweezers and ease it into the substrate instead of gripping the middle.

Frequently asked questions

How much light does Red Ludwigia need?: High light, around 60–90 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 Red Ludwigia need CO₂?: It is recommended. Marked "recommended": it survives without, but visibly stalls, lengthens between nodes and loses colour.
What water does Red Ludwigia 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 Red Ludwigia grow, and where does it go?: Growth rate: fast. Placement: midground / background. Substrate: substrate required, reaching about 20–40 cm. Difficulty: beginner.