People treat Duckweed like decoration. It is closer to a slow, quiet pet that responds to the water you keep. The Lemna minor Duckweed is a workhorse plant for a reason: it tolerates a wide range of conditions and still looks good doing it.

At a glance

Lighthigh
Temperature22 to 28 °C
pH6.0 to 7.5
Height1 to 3 cm
CO₂not required
Growthvery fast

Planting

Plant Duckweed with the crown or rhizome clear of the substrate — burying it rots the base. In a 31-gallon tank, position it mid-ground or background depending on its height. Weaker setups do fine; pair it with our choosing the right aquarium filter (sponge, hob or canister) guide for a layered look.

Light and CO₂

Run 8 hours of light a day on a timer to avoid algae swings. Duckweed grows under high light and not required, though a small, steady dose of liquid fertiliser every 4 weeks pushes denser growth.

Propagation

It multiplies by budding; thin it weekly to stop coverage.

Common issues

Yellowing lower leaves usually mean a nutrient gap, not too little light. Trim dying leaves at the base, keep nitrates around 10 to 20 ppm, and avoid moving the plant every week — the cloudy eye and popeye: what the swollen eye means explains why stability beats tinkering.