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Plant appearance can vary with lighting, nutrients, CO₂, and whether it is grown submerged or emersed.
easylow lightNo CO2fast growthfloating
Duckweed
Lemna minor
Duckweed is the smallest flowering plant and one of the easiest floating plants to maintain. It is very fast-growing, highly effective at nutrient export, and shades the tank well. A double-edged plant: extremely useful for nutrient control, but notoriously hard to remove once introduced.
Evidence: verifiedConfidence: high
Care at a glance
Water parameters
Beginner guidance
Good for tanks with goldfish or other herbivores that will eat it as food. Nearly impossible to fully eradicate, only introduce if you accept a permanent presence. Skimmer/overflow tanks spread it fast.
Cautions
- Very difficult to remove once established.
- Can clog filter inlets if sucked in.
Sources
- Lemna minor. Wikipedia — Worldwide species: smallest angiosperms, rapid nitrate uptake, and aquarium use as floating plant.
Fish whose water overlaps
Peaceful freshwater species with overlapping temperature and pH — still run a pair check for the real mix.
Similar plants
- Java Mosseasy · low light · no CO2
- Anubiaseasy · low light · no CO2
- Java Ferneasy · low light · no CO2
- Amazon Swordeasy · medium light · no CO2
- Hornworteasy · low light · no CO2
- Water Wisteriaeasy · medium light · no CO2
Plan the tank around this plant
Set a 5L+ footprint, then verify livestock before you buy Duckweed.
Tank hubs: 30L
Related plant guides
Easy beginner aquarium plantsLow-light aquarium plantsPlants for shrimp tanks
Common questions about Duckweed
- Does Duckweed need CO2?
- No. Duckweed grows in low-tech tanks without CO2 injection or liquid carbon supplementation.
- What light does Duckweed need?
- Duckweed is a low-light plant. Standard aquarium LEDs cover this with room to spare. It is one of the plants you can light from a basic shop hood and still get growth.
- Is Duckweed beginner-friendly?
- Duckweed is rated easy for difficulty. Good for tanks with goldfish or other herbivores that will eat it as food. Nearly impossible to fully eradicate, only introduce if you accept a permanent presence. Skimmer/overflow tanks spread it fast.
- Is Duckweed safe for shrimp?
- Yes. Duckweed is safe in shrimp tanks. The usual quarantine still applies: any plant from a commercial nursery should be soaked and rinsed first to flush copper and pesticide residue.