Sunset Hygrophila (Hygrophila polysperma 'Rosanervig')

Photo: Wikimedia Commons / CC BY-SA 3.0

Sunset Hygrophila Care

Hygrophila polysperma 'Rosanervig' · Acanthaceae

🐾 Pet-safe 🎯 Moderate ☀️ Bright with some direct sun 💧 Every 7 days

🕮 6 min read 🕓 Last reviewed: 2026-08-23

Care at a glance

Light

Bright with some direct sun

Temperature

20–28 °C (68–82 °F)

Soil

a nutrient-rich aquarium substrate (or attached to wood/rock)

Difficulty

Moderate

Mature size

15–50 cm (6–20 in)

Pet safety

Pet-safe

Care effort High

The short version

A little attention keeps it happy.
Give it Bright with some direct sun.
Water every 7–7 days.
Safe around cats and dogs.

The Sunset Hygrophila (Hygrophila polysperma 'Rosanervig') is an aquatic plant grown submerged in freshwater aquariums. It comes from Cultivated hybrid and is rated Moderate to keep, reaching 15–50 cm. Here is how to grow it underwater — lighting, substrate, CO₂, placement and propagation.

Also known asHygrophila polysperma 'Rosanervig'サンセットハイグロ日落小竹叶Hygrophila RosanervigSunset-Wasserfreund

📋Quick facts

Growth rate	Fast
Mature size	15–50 cm (6–20 in)
Native region	Cultivated hybrid
Plant family	Acanthaceae
Toxicity	Non-toxic
Air-purifying	No
Ideal for	homes with pets, a pop of colour

⚖️Pros & cons

Pros

Non-toxic to cats and dogs
Fast, rewarding growth
Flowers indoors

Cons

Needs high humidity to look its best
Needs a bright, sunny spot

🐟Growing it in an aquarium

Keep the water at 20–28 °C. Stable, gently moving water and regular partial water changes keep it healthy; sudden swings in temperature or chemistry cause melting.

Light

Give it Bright with some direct sun-equivalent aquarium lighting. Low-tech tanks suit undemanding species; brighter light (and often CO₂) brings out the best colour and compact growth but also feeds algae, so balance it carefully.

Soil

Plant it in a nutrient-rich aquarium substrate (or attached to wood/rock). Rooted species are hungry feeders — use root tabs or a liquid aquarium fertiliser (and CO₂ for demanding types). Epiphytes like Anubias, Java fern and Bucephalandra must NOT be buried: tie or glue their rhizome to wood or rock, or they rot.

Its size and habit suit a spot in the foreground, midground or background depending on how tall it grows; trim and replant tops to keep it dense.

✂️How to propagate, step by step

Spring and early summer, during active growth, give the best success. Here is how to do it, step by step:

stem cuttings in water

Choose a healthy stem and cut a 10–15 cm piece just below a leaf node with clean, sharp scissors.
Strip the leaves off the lower third so no foliage will sit under water.
Stand the cutting in a glass of room-temperature water with at least one node submerged.
Keep it in bright, indirect light and refresh the water every few days.
When the roots are 3–5 cm long (usually 2–4 weeks), pot it into moist mix and keep it a little humid while it settles in.

🔬Classification

Plant type	Aquatic plant
Genus	Hygrophila
Family	Acanthaceae · Acanthaceae
Native to	Cultivated hybrid

🩺Common problems

Symptom	Likely cause	What to do
Algae on leaves or glass	Too much light or excess nutrients in the water	Cut the lighting period, reduce feeding, and add algae-eating clean-up crew.
Pale or faded leaves	Too much direct sun, or a nutrient gap	Move it out of harsh sun and feed during the growing season.
Melting or dissolving leaves	Shock from a new tank (common when settling in)	Be patient — trim mushy leaves; new submerged growth usually follows.

🩺 Plant Doctor →

🐛Pests & prevention

The usual indoor pests are spider mites (fine webbing, speckled leaves), mealybugs (white cotton-wool tufts), scale (small brown bumps), and fungus gnats (tiny flies from soggy soil). Inspect any new plant before it joins the others, wipe the leaves now and then, and let the topsoil dry to keep gnats away. At the first sign, isolate the plant, wipe or rinse off what you can, and treat with insecticidal soap or neem oil every week until it is clear.

🐾Is it safe for pets?

Good news for pet owners: the Sunset Hygrophila is considered non-toxic to both cats and dogs by the ASPCA. It is one of the safer choices for homes with animals, though eating any plant can still cause mild stomach upset.

Toxicity information is a general guide based on ASPCA data. If your pet or child may have eaten any part of a plant, contact a vet or poison control right away.