Common duckweed
The smallest and fastest floating plant, and effectively impossible to remove once introduced.
Requirements
- Scientific name
- Lemna minor
- Family
- Araceae
- Light
- Low
- CO₂
- Not required
- Nutrients
- moderate
- Growth rate
- Very fast
- Placement
- Floating
- Feeding
- water column
- Temperature
- 10–30 °C
- pH
- 5.5–8.5
- Hardness
- 1–25 °dGH
Identity
- Common name
- Common duckweed
- Scientific name
- Lemna minor
- Family
- Araceae
How to plant it
The commonest way to kill an aquarium plant is to install it wrongly. This is the first thing to get right.
Float on the surface
Nutrition reaches this plant mainly through the water column, so liquid fertiliser matters more than substrate nutrition.
Growing conditions
| Input | Requirement | Notes |
|---|---|---|
| Light | Low | Match plants to the light you have rather than raising light to suit the plant — that grows algae. |
| CO₂ | Not required | Not a requirement, though growth is faster with it. |
| Nutrients | moderate | Dose a complete liquid fertiliser. |
| Temperature | 10–30 °C | |
| pH | 5.5–8.5 | |
| Hardness | 1–25 °dGH | |
| Growth rate | Very fast |
Propagation
Vegetative division; a population can double in days.
Common problems
- cannot be eradicated
- blocks all light
- clogs filters
Work from the observation: melting, yellow leaves, holes in leaves and poor growth.
Fish and invertebrate compatibility
- Resists grazing
- poor
- Resists digging
- excellent
Worth knowing
- Excellent nutrient export and excellent duck food; a permanent resident once it arrives.
- Arrives as a hitchhiker on almost any plant purchase. Inspect and quarantine new plants if you want to avoid it.
Evidence
| Claim | Value | Evidence type | Confidence | Source |
|---|---|---|---|---|
| scientific name | Lemna minor | Observed / measured | high confidence | Plants of the World Online |
| temperature | 10–30 °C | Aquarium-literature consensus | high confidence | AquariumHQ husbandry synthesis |
| light requirement | low | Aquarium-literature consensus | high confidence | AquariumHQ husbandry synthesis |
| co2 requirement | not-required | Aquarium-literature consensus | high confidence | AquariumHQ husbandry synthesis |
| growth rate | very-fast | Aquarium-literature consensus | high confidence | AquariumHQ husbandry synthesis |
| placement | floating | Aquarium-literature consensus | high confidence | AquariumHQ husbandry synthesis |
| ph | 5.5–8.5 pH | Aquarium-literature consensus | high confidence | AquariumHQ husbandry synthesis |
| general hardness | 1–25 °dGH | Aquarium-literature consensus | high confidence | AquariumHQ husbandry synthesis |
Why we say this
What each figure on this page rests on, and how far that is from being independently established.
Every figure on this page has a provenance. Open any claim to see what AquariumHQ holds for it, which sources say what, and what a claim of that kind actually needs. Different claims need different evidence: an accepted scientific name is settled by one authority, while a legal restriction needs a current primary instrument. A single source is often the right answer rather than a thin one. Light and CO2 categories are aquarium conventions rather than measurements, and are labelled as such — AquariumHQ has taken no PAR readings and does not publish figures it has not taken.
scientific nameAquariumHQ's own position, externally checkableLimited evidence — treat with caution.
AquariumHQ's own position on a claim an external source could support.
What this kind of claim needs: accepted botanical name — 1 authoritative source in an appropriate context. This class needs 1 independent origin of at least primary-compilation authority, and 0 are held.
What would improve this: Go and read a source. This is reachable and has not been reached.
temperatureAquariumHQ's own position, externally checkableAquariumHQ's own position, derived from evidenced inputs.
AquariumHQ's own position on a claim an external source could support.
What this kind of claim needs: how to grow the plant — no external source is required, provided AquariumHQ shows its reasoning. No external source is required for this class. AquariumHQ's position stands on its stated reasoning.
What would improve this: Go and read a source. This is reachable and has not been reached.
light requirementAquariumHQ's judgement — no authority publishes thisAquariumHQ's own position, derived from evidenced inputs.
No external authority publishes this. The rationale carries the reasoning.
What this kind of claim needs: how to grow the plant — no external source is required, provided AquariumHQ shows its reasoning. No external source is required for this class. AquariumHQ's position stands on its stated reasoning.
What would improve this: Keep the rationale current. There is no source to find.
co2 requirementAquariumHQ's judgement — no authority publishes thisAquariumHQ's own position, derived from evidenced inputs.
No external authority publishes this. The rationale carries the reasoning.
What this kind of claim needs: how to grow the plant — no external source is required, provided AquariumHQ shows its reasoning. No external source is required for this class. AquariumHQ's position stands on its stated reasoning.
What would improve this: Keep the rationale current. There is no source to find.
growth rateAquariumHQ's judgement — no authority publishes thisAquariumHQ's own position, derived from evidenced inputs.
No external authority publishes this. The rationale carries the reasoning.
What this kind of claim needs: how to grow the plant — no external source is required, provided AquariumHQ shows its reasoning. No external source is required for this class. AquariumHQ's position stands on its stated reasoning.
What would improve this: Keep the rationale current. There is no source to find.
placementAquariumHQ's judgement — no authority publishes thisAquariumHQ's own position, derived from evidenced inputs.
No external authority publishes this. The rationale carries the reasoning.
What this kind of claim needs: how to grow the plant — no external source is required, provided AquariumHQ shows its reasoning. No external source is required for this class. AquariumHQ's position stands on its stated reasoning.
What would improve this: Keep the rationale current. There is no source to find.
phAquariumHQ's own position, externally checkableAquariumHQ's own position, derived from evidenced inputs.
AquariumHQ's own position on a claim an external source could support.
What this kind of claim needs: how to grow the plant — no external source is required, provided AquariumHQ shows its reasoning. No external source is required for this class. AquariumHQ's position stands on its stated reasoning.
What would improve this: Go and read a source. This is reachable and has not been reached.
general hardnessAquariumHQ's own position, externally checkableAquariumHQ's own position, derived from evidenced inputs.
AquariumHQ's own position on a claim an external source could support.
What this kind of claim needs: how to grow the plant — no external source is required, provided AquariumHQ shows its reasoning. No external source is required for this class. AquariumHQ's position stands on its stated reasoning.
What would improve this: Go and read a source. This is reachable and has not been reached.