Duckweed
Lemna minor
Also known as Lemna, Common Duckweed, Lesser Duckweed
Plantae›Tracheophyta›Magnoliopsida›Alismatales›Araceae
📍 Worldwide
Duckweed is the smallest flowering plant and one of the fastest-growing aquatic plants available. It provides effective nutrient export and surface shade while serving as live food for herbivorous fish. It can quickly cover the entire surface if not managed.
Community Photos
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by @isabellekaulback
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Tanks keeping this 🌿
Growing in 13 tanksCommunity tanks featuring Duckweed.
Compatible Livestock
Herbivorous algae eater that won't damage duckweed; benefits from shade provided by plant coverage
Shrimp graze on algae and detritus without harming duckweed; thrive in shaded environments
Appreciates surface vegetation for shelter; won't uproot or consume duckweed
Small peaceful fish that benefit from duckweed shade and won't disturb the plant
Excellent algae control companion; won't damage duckweed and prefers planted environments
Companion plant with similar low-light tolerance; creates dense cover when grown together
Common Diseases
Nutrient Deficiency
Yellowing fronds, stunted growth, pale coloration, reduced reproduction rate
Dose all-in-one liquid fertilizer weekly; test water for nitrogen, phosphorus, and iron levels; increase water change frequency to boost fish bioload
Algae Overgrowth on Fronds
Green or brown algae coating duckweed surfaces, reduced light penetration, plant decline
Increase water circulation with aeration; reduce light duration to 8-10 hours daily; manually remove heavily algae-covered fronds; introduce algae-eating fish like Otocinclus or Siamese Algae Eater
Root Rot (Minimal Risk)
Fronds detaching prematurely, mushy appearance, foul odor from decaying plant matter
Improve water circulation and oxygenation; remove dead fronds immediately; ensure water parameters remain stable (pH 5.0-8.0); perform 25% water changes weekly
Excessive Growth/Choking
Complete surface coverage blocking light, gas exchange reduction, plant pileup
Harvest 30-50% of biomass weekly; reduce fertilizer dosing; lower light intensity or duration; ensure adequate water flow to prevent stagnation
Tips from the community 💡
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Quick Facts
- co2
- Not required
- diet
- Water column nutrient uptake
- light
- Low to high
- tank size
- No minimum – floating
- growth rate
- Extremely fast
Water it likes
- ph
- 5.0–8.0
- ammonia
- 0 ppm
- nitrate
- <60 ppm
- hardness
- 1–25 dGH
- temperature
- 50–86°F (10–30°C)
Legality
No state or federal restrictions on record for this species.
Not legal advice, and possibly incomplete or out of date. Rules vary by state and locality and change over time — always confirm the current regulations with your state wildlife or agriculture agency before buying, keeping, or shipping this species.