Ludwigia Repens

Ludwigia repens is a versatile stem plant from North America, where it grows in shallow freshwater streams, ponds, and margins. In the aquarium, its coloration is highly light-dependent: in low light the leaves are olive-green on the upper surface and light reddish on the underside; in medium light they become more bronze-green; under strong light with iron supplementation and CO2, the leaves turn intensely red-orange to scarlet, making it one of the most reliable and accessible red plants in the hobby.

Ludwigia repens has been grown in aquariums for decades and is prized for its combination of color potential and relative ease of care compared to more demanding red plants. It grows without CO2 in medium light (in shades of green-bronze), and achieves its best red coloration with CO2 and strong light — but the transition between these conditions is gradual rather than absolute, giving aquarists flexibility.

The plant grows upright with opposite pairs of oval leaves. It grows moderately fast under good conditions and requires periodic trimming and replanting of tops to maintain a bushy, full appearance. Regular liquid fertilization with iron and trace elements is important for maintaining red coloration.

Ludwigia repens is suitable for aquarists at all levels, from beginners in low-tech tanks (where it will be green) to advanced aquascapers seeking red-orange accents in high-tech setups.

Light: Low to high light (10–80 PAR). Color is light-dependent: green in low light, orange-red in high light. CO2 and iron enhance red coloration.

CO2: Optional for growth, but CO2 injection (15–25 mg/L) with high light achieves maximum red coloration.

Nutrients: Regular liquid fertilization with iron and micronutrients enhances red-orange coloration. NPK supplementation supports healthy growth.

Placement: Background to midground depending on tank size. Grows to 30–50 cm in height. Groups of 5–10 stems provide best visual impact.

Maintenance: Trim tops regularly. Replant trimmed tops for bushier groupings. Remove bare lower stems periodically.

Water Parameters: pH 6.0–8.0, temperature 20–28°C. Adaptable to a wide range of conditions.