About the species

Hygrophila polysperma 'Rosanervig' is recognised by its pink, marbled leaves with chalk-white veins. The stems reach 20–40 centimetres tall and five to eight centimetres wide. The pale veining is probably caused by a virus that blocks chlorophyll production in the cells around the ribs, but it is entirely harmless to the other plants in the aquarium.

Facts

• Latin name: Hygrophila polysperma 'Rosanervig'
• Plant type: Stem plant
• Origin: Cultivated variety
• Height: 20–30 cm
• Growth rate: Medium
• Position: Background

Light requirement

Low light requirement. It manages with the lighting that comes with most aquariums and is happy in partial shade behind or beneath taller plants. Strong lighting does not harm it, but raises the risk of algae on the leaves because the plant cannot use all the available light.

CO₂ & nutrition

Added CO₂ is recommended — Tropica reckons 6–14 mg/l as a medium requirement. The plant can be grown without, but then grows more slowly and loses some of its colour. Supplement with liquid fertiliser weekly and keep iron and potassium levels up.

Planting

Split the bunch and set the stems one by one, about two centimetres into the substrate and two to three centimetres apart. Removing the lowest leaves first stops them rotting in the substrate. A group of five to ten stems looks far better straight away than single plants.

Carefully remove the pot and rinse the rock wool off the roots before planting — leftover rock wool can otherwise hinder rooting.

Care & propagation

Top the plant when it reaches the height you want and replant the cuttings — that propagates it and gives a denser group at the same time. Trim regularly so light reaches the lower leaves, and discard the old lower sections once they start thinning out.

Position in the aquarium

Given its mature height it belongs at the back or along the sides, where it forms a dense wall of greenery and hides equipment. In a smaller aquarium it can also be used as a solitaire in one corner.

Difficulty level

🟢 Easy — grows in most aquariums without CO₂ and under ordinary lighting.

Delivery format

Delivered as a pot grown submerged, with the roots in rock wool. The pot holds several plants or stems that can be divided and planted separately.

Recommendation

An unusually easy way to bring pink into the aquarium, since the variety is just as undemanding as ordinary polysperma. Cut off any shoot that reverts to plain green and give it intense light for the deepest pink leaves.