Water hyacinth (Pontederia crassipes) care guide

Group
Plants
Other names
Eichhornia crassipes, Common water hyacinth, Eichhornia speciosa, Piaropus crassipes
Family
Pontederiaceae (pickerelweed family)
Origin
Tropical and subtropical South America
Water
freshwater
Maximum size
100 cm
Temperature
12–33°C
pH
5–7.5
Hardness
2–15 dGH
Care level
beginner
Lighting
Very strong light; CO2 not needed (it takes CO2 from the air)
Flow
Still or slow surface water

Care

Legal note: this plant may not be sold on Aquatic-Auctions to buyers in Great Britain. It is on the GB list of invasive species (check GOV.UK for the current rules). Water hyacinth, formerly Eichhornia crassipes, is a free-floating perennial from tropical and subtropical South America. It has glossy, rounded leaves about 10–20 cm across on swollen, air-filled stalks, long feathery roots and spikes of lilac flowers, and can stand up to about 1 m above the water. It is one of the fastest-growing plants known: mats can double in one to two weeks. It grows from about 12 °C, best at 25–30 °C, and stops above about 33–35 °C; frost kills the leaves. It likes pH roughly 5–7.5 and will not grow in brackish water. It needs very strong light and plenty of nutrients, so it is a summer pond plant rather than an aquarium plant. The hardness figure is our estimate, not from the sources. It is invasive across much of the warm world. The EU has banned its sale, import, cultivation and release since 2016, and New Zealand restricts it too. Sources: Wikipedia (en.wikipedia.org/wiki/Pontederiacrassipes); Wikipedia, List of freshwater aquarium plant species. Checked October 2026.

Breeding

Spreads mainly by runners (stolons) that form new plants beside the parent, and also by seed; a plant can produce thousands of seeds a year that stay viable for decades.

Compatibility and tank mates

Its roots shelter fry and are used as spawning sites, and goldfish and koi nibble them. It needs open water and space above it, so it does not suit covered aquariums. Do not keep it where the law forbids it, and never put it in outdoor ponds that could overflow into the wild.

Last updated 8 October 2026. Community-edited care guide on Aquatic-Auctions.

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