Hygrophila polysperma 'Rosanervig'
Sunset Hygro


Background History

Hygrophila polysperma ‘Rosanervig’ is a beautiful domestic cultivated derivative of Hygrophila polysperma. The plant contains distinctive wide red/pink leaves and abnormally white leaf veins which is hypothesized to be caused by a virus that prevents chlorophyll from being produced in that area.  This virus is harmless and not pathogenic to other plants in the aquarium.   

In most areas of the United States, Hygrophila polysperma is considered to be an invasive species due to its growth rate and tendency to disrupt waterways, drainage systems, and ecosystems. 

This plant is commonly known as Tropical Sunset or Sunset Hygro.

Growth Characteristics

Hygrophila polysperma ‘Rosanervig’ is one of the rare easy to grow colorful aquatic plants available to hobbyists.  It can grow in a wide range of aquarium parameters including pH, temperature, lighting, carbon dioxide and nutrients.  The stem can gain a height of 12 inches (30 cm) and a plant width of 3 inches (10 cm).

In order to encourage the deep red hues in the leaves, Hygrophila polysperma ‘Rosanervig’ must be exposed to intense light and low nitrates.  In those conditions, this plant will have a rapid growth rate and require weekly trimming to maintain an orderly appearance.

In lower lighting conditions, Hygrophila polysperma ‘Rosanervig’ is more manageable, but the red hues may be only a slight pink on the leaves that are closest to the lighting source.

Aquascaping Application

Hygrophila polysperma ‘Rosanervig’ is a somewhat difficult plant to maintain in an aquascape due to its rapid growth rate in high light aquariums.  However, this plant can be trained through regular trimmings to form a compact bush that can be placed in the background or midground areas of an aquascape.

Photo Credit: Jose A. Flores

Plant Profile
Scientific Name: Hygrophila polysperma 'Rosanervig'
Common Name: Sunset Hygro
Difficulty: Very Easy
CO2 Requirements: Low
Lighting Requirements: Medium
Plant Arrangement: Background
Growth Rate: Fast
Family: Acanthaceae
Genus: Hygrophilia
Origin: Asia
Plant Type: Stem
Water Hardness: Medium (GH = 9-13 dH)