floating plant · easy

Duckweed: height, light, CO₂ & fish that eat it

Lemna minor has no height published by our sources and floats at the surface. It's rated for low–high light, and injected CO₂ is not needed. Temperature 39–86°F, pH 5–9.

Try it in the tank builder See which fish eat it

How tall it grows

It floats, so height doesn't limit which tank it suits.

Will it fit your tank?

Fits any tank. It floats at the surface. Thin it out so plants below still get light.

Check it with your fish →

Quick facts

Grows to: not published
Height basis: —
Where it goes: floating
Light: low–high light
Injected CO₂: not needed
Growth: fast
Difficulty: easy
Temperature: 39–86°F
pH: 5–9
Hardness: not published
Feeds through: not published
Also sold as: Common duckweed

Planting tip: Very hard to remove once introduced; a single frond can start a population, so net it out regularly.

Fish and Duckweed

Checked with the same rules as our tank builder: plant-eating and digging named in each fish's sources, plus temperature and pH overlap.

Eats it (9)

May uproot it (0)

Not rooted, so digging fish can't pull it up.

Different water (0)

Every fish shares some temperature and pH range with it.

Fish that leave it alone and share its water (97)

Pearl Gourami Angelfish German Blue Ram Bolivian Ram Kribensis Electric Yellow Lab Bronze Cory Panda Cory Pygmy Cory Julii Cory Bristlenose Pleco Otocinclus Kuhli Loach Hillstream Loach Siamese Algae Eater Cherry Shrimp Amano Shrimp Nerite Snail Mystery Snail Glowlight Tetra Lemon Tetra Congo Tetra Black Neon Tetra Chili Rasbora Boesemani Rainbowfish Dwarf Neon Rainbowfish African Dwarf Frog Pea Puffer Ghost Shrimp Iridescent Shark Bala Shark Red-Tail Shark Rainbow Shark Oscar Chinese Algae Eater Neon Tetra Cardinal Tetra Black Skirt Tetra Serpae Tetra Rummy-nose Tetra Ember Tetra Harlequin Rasbora Zebra Danio Celestial Pearl Danio White Cloud Mountain Minnow Cherry Barb Tiger Barb Guppy Endler's Livebearer Molly Platy Swordtail Betta Dwarf Gourami Honey Gourami Head-and-tail-light Tetra Bleeding Heart Tetra Diamond Tetra Silver Tip Tetra Pristella Tetra Penguin Tetra Silver Hatchetfish Marbled Hatchetfish Lambchop Rasbora Pearl Danio Giant Danio Scissortail Rasbora Gold Barb Rosy Barb Odessa Barb Denison Barb Variatus Platy Three-spot Gourami Moonlight Gourami Sparkling Gourami Paradise Fish Cockatoo Dwarf Cichlid Firemouth Cichlid Electric Blue Acara Discus Blood Parrot Cichlid Peppered Cory Sterbai Cory Clown Pleco Pictus Catfish Glass Catfish Upside-down Catfish Weather Loach Forktail Blue-eye Clown Killifish Bumblebee Goby Crystal Red Shrimp Bamboo Shrimp Ramshorn Snail Malaysian Trumpet Snail Assassin Snail Japanese Trapdoor Snail

Common questions

How tall does Duckweed grow?

Our sources don't publish a height for Duckweed.

How much light does Duckweed need?

It's rated for low–high light. Growers often disagree on light, so this is the full range across our sources.

Does Duckweed need CO₂?

No. Its sources rate its CO₂ need as low, and it grows without injection.

Which fish eat Duckweed?

In our database, Convict Cichlid, Common Pleco, Common / Comet Goldfish, Clown Loach, Tinfoil Barb, Buenos Aires Tetra, Kissing Gourami, Yoyo Loach, Fancy Goldfish are flagged as eating live plants. Tough-leaved anubias usually hold up better.

Gear for Duckweed

PlantLive Duckweed. Compare sellers and pot sizes.Find on Amazon →LightA basic aquarium LED is enough for low light.Find on Amazon →FertilizerA liquid fertilizer for plants that feed from the water.Find on Amazon →

As an Amazon Associate, AquariumSetup earns from qualifying purchases. Links open Amazon search results so you can compare current options.

Sources

Values come from these pages, in our own words. Where growers disagree, we show the full range. Last reviewed 2026-10-17.

flowgrow.de /db/aquaticplants/lemna-minor
flowgrow.de /db/aquaticplants/lemna-spp
aquasabi.com /aquascaping-wiki_aquatic-plants_getting-rid-of-duckweed
minnesotawildflowers.info /aquatic/common-duckweed