Pistia Stratiotes/ Water Lettuce

Quick facts

Identity

Also known as

Nile cabbage; Water cabbage; Shellflower

Synonyms

Pistia occidentalis; Pistia texana

Environment

Freshwater

Native to

Pantropical, exact origin debated (possibly South America or Africa)

Habitat

Still and slow-moving tropical and subtropical waters including ponds, ditches, lakes, and river backwaters

Sourcing

Captive-bred

Conservation

Not Evaluated

Care

Care level

Easy

Growth form

Floating

Max height

2 – 6 in (5.1 – 15 cm)

Spread

6 in (15 cm)

Growth rate

Fast

Placement

Floating

Water

Temperature

72 – 86 °F (22 – 30 °C)

pH

6.0 – 7.5

GH

3 – 12 dGH

dKH

3 – 8 dKH

Flow

Low

Light

Medium

CO₂

Not needed

Planting

Substrate

Not needed

Feeds from

Water column

Fertilizer needs

Medium

Colors

Green

Feeding & breeding

Propagation

Runners, Plantlets

Something wrong or missing? Submit a correction

Care guide

Overview

Suits nutrient-heavy tanks needing a fast nitrate sponge or a breeding setup wanting cover for fry and shrimp. Pale green rosettes resemble small heads of lettuce, floating on the surface while long feathery roots trail below for biofilm grazing. Fast-growing and undemanding, it needs open-top ventilation, moderate light, and regular thinning to keep from blanketing the surface.

Care

Water lettuce is dropped directly onto the water surface rather than planted, where its rosette of velvety leaves floats while a curtain of feathery roots trails below. It grows best in an open-top tank with medium to high light and some air movement; closed lids trap condensation that drips onto the crown and causes rot. Regular thinning is needed since the plant multiplies quickly by daughter rosettes and will cover the whole surface, shading out anything growing beneath it. It tolerates a wide range of hardness and pH but is intolerant of cold water and strong surface agitation, which can swamp the leaves.

Planting & trimming

No planting is required; simply float the rosette on the water surface with room for the roots to hang freely. Keep some clearance from filter outflows and powerheads since strong flow can submerge the leaves or shred the roots. Thin the colony regularly by removing excess daughter rosettes to prevent it from blanketing the entire surface.

Fertilizing

Roots absorb nutrients directly from the water column, so root tabs are unnecessary and liquid fertilization is the appropriate route. It is a heavy feeder on nitrate and benefits from supplemental iron and micronutrients, especially in tanks without much fish waste. Yellowing new growth is a common sign of iron or micronutrient deficiency, while pale, stunted rosettes usually point to insufficient light.

Propagation

Propagation is vegetative, with the mother rosette sending out short stolons that bud off daughter plants which can be separated once they have their own root systems. Under good light and nutrient levels this happens rapidly, and a single rosette can multiply into a dense mat within a few weeks. Seed production occurs but is rarely relevant in aquarium culture.

Problems

Overhead condensation and strong surface spray are the most common causes of failure, pooling on the crown and causing the leaves to melt and rot. Low light leads to small, deteriorating rosettes, while adequate light and nutrients keep the foliage compact and full. Roots naturally darken from white to tan or blackish as they age or collect sediment, which is normal and not a sign of disease.

Sources

1. Dwarf water lettuce care: light, CO2 and placement · TankBud
2. Water lettuce (Pistia stratiotes) - Scale & Stem
3. Water Lettuce (Pistia stratiotes) Care & Tank Mates, Fin & Stem
4. Dwarf Water Lettuce: Caring for Pistia stratiotes

More Floating plants

Azolla CarolinianaHydrocleys Nymphoides Water PoppyPhyllanthus Fluitans Red Root FloaterSalvinia CucullataSalvinia Natans/ Floating Fern