Hygrophila polysperma ‘Rosanervig’

Scientific name: Hygrophila polysperma ‘Rosanervig’

Family: Acanthaceae

Maximum size reached under cultivation conditions: 20 - 50 cm (7.87 - 19.69 inch)

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Recommended pH range for the species: 6.1 - 7.7

Recommended water hardness (dGH): 5 - 18°N (89.29 - 321.43ppm)

0°C 32°F30°C 86°F

Recommended temperature: 20 - 26 °C (68 - 78.8°F)

Reproduction of the plant: Cuttings

Origin (in the wild): Cultivated form / Hybrid

How fast these plants grow: Fast

Recommended substrate: Fine gravel

Demands on lighting: Medium

Ideal placement in a fish tank: Background

Common Name

Sunset Hygro

Origin

Hygrophila polysperma ‘Rosanervig’ is a cultivated variety of Hygrophila polysperma, originally developed for its striking appearance. Unlike the wild form, this cultivar does not occur naturally in the wild. It is maintained through propagation in aquariums and nurseries.

Growing Conditions

This plant thrives in both submerged and emersed conditions. When grown submerged under medium to bright lighting, it displays vibrant pinkish hues with characteristic light-colored or white veins. The stronger the lighting, the more intense the coloration becomes. In emersed conditions, it can produce small purple flowers, though this usually results in the loss of some lower leaves.

Hygrophila polysperma ‘Rosanervig’ prefers nutrient-rich water and substrate, with a pH range of 6.1 to 7.7 and water hardness between 5 - 18 dGH. The ideal temperature range is 20 - 26 °C (68 - 78.8°F). Although CO₂ supplementation is not strictly required, it can further enhance coloration and growth rate.

Planting Area

Reaching heights of 20 to 50 cm (7.87 - 19.69 inches), this plant is best suited for the background of aquariums. When planted in dense groups, it creates a colorful and dynamic backdrop. Regular pruning is recommended to maintain compact growth and prevent shading of smaller plants.

Propagation

Hygrophila polysperma ‘Rosanervig’ propagates easily via cuttings. Take a healthy stem from the mother plant, remove the lower leaves, and insert it gently into the substrate. Roots will typically form quickly, even without additional support. Under optimal conditions, new plants may also grow from leaves that have settled on the substrate.

Difficulty

This plant is considered easy to moderate in terms of care. It is suitable for beginners who provide adequate lighting and nutrients. However, for the best coloration, a moderate level of lighting is necessary. If nutrients are lacking, the plant may lose color and shed its lower leaves.

Short Description

Hygrophila polysperma ‘Rosanervig’, also known as Sunset Hygro, is a fast-growing and visually striking aquarium plant prized for its pink hues and contrasting veins. It grows well in a variety of water conditions and adapts easily to submerged or emersed growth.

Thanks to its rapid growth and decorative appearance, it is a popular choice among aquascapers. However, due to its invasive potential in some regions, proper trimming and responsible disposal of plant material are highly recommended to avoid spreading it into local waterways.

Frequently Asked Questions about Hygrophila polysperma ‘Rosanervig’

• Is Hygrophila polysperma ‘Rosanervig’ a natural species?

  No, it is a cultivated variant of Hygrophila polysperma, selected for its attractive coloration and veined leaves. It does not occur naturally in the wild.

• Does this plant need CO₂ to grow well?

  CO₂ is not necessary, but it helps enhance coloration and speeds up growth. The plant will grow under medium lighting without CO₂, but the pink hues will be less intense.

• Why are the leaves turning green instead of pink?

  Insufficient lighting is the most common reason. To achieve the signature pink color, provide bright lighting and a nutrient-rich environment.

• Can I grow this plant above water?

  Yes, it grows well in emersed conditions and may even flower. However, it may lose its lower leaves and become less attractive for aquascaping.

• How often should I trim Hygrophila polysperma ‘Rosanervig’?

  Regular trimming (every 1–2 weeks) helps maintain bushy growth and prevents the plant from overshadowing others. Trimmed stems can be replanted as cuttings.

• Is it invasive?

  Yes, in some countries it is considered invasive due to its fast growth. Always dispose of trimmings responsibly and never release this plant into natural waterways.

Image was provided by Oliver.