Aquarium plant

Hornwort

Hornwort (Ceratophyllum demersum) aquarium plant care. low light, CO2 no, beginner difficulty.

Hornwort TL;DR

Light: low · CO2: no · Difficulty: beginner.

Hornwort (Ceratophyllum demersum) is a popular aquarium plant.

What lighting does Hornwort need?

Hornwort grows best under low lighting. Target PAR: 15-30 at substrate level.

Is CO2 required for Hornwort?

No CO2 injection required - thrives in standard low-tech tanks.

What substrate and nutrients does Hornwort need?

Tolerates inert substrate with occasional root tabs. Liquid fertilizer optional.

How is Hornwort propagated?

Hornwort propagates by cutting healthy stems and replanting in substrate.

What mistakes should you avoid with Hornwort?

Burying the rhizome (rots), insufficient light, skipping CO2 in high-tech setups, neglecting weekly water changes (algae bloom).

Where to buy

Browse Hornwort from vetted Fast Aquatics plant vendors.

Hornwort FAQ

How much light does Hornwort need?

Hornwort is rated as a low-light plant. Low light means a basic aquarium LED is usually enough, and adding much more light without matching fertilizer tends to feed algae on the leaves before it speeds up the plant. CO2 is not needed for it, and its care difficulty is listed as beginner.

Does Hornwort need CO2?

No. Hornwort does not need injected CO2, so it suits low-tech tanks without a CO2 system. It is a low-light plant. For nutrients: tolerates inert substrate with occasional root tabs. Liquid fertilizer optional. Keep light, CO2 and fertilizer in balance, because raising one without the others is the most common cause of algae in planted tanks.

How do you propagate Hornwort?

Hornwort propagates by cutting healthy stems and replanting in substrate. Trim stems just above a leaf node, push the cut tops into the substrate, and the trimmed base will usually branch and regrow. New growth comes in fastest when the tank matches its needs: low light, with CO2 not needed.

Is Hornwort good for beginners?

Yes. Hornwort is listed at beginner difficulty. It needs low light, CO2 is not needed, and for nutrients: tolerates inert substrate with occasional root tabs. Liquid fertilizer optional. Stable light, nutrients and water changes matter more than any single product. Check these needs against your current setup before buying.

Sources and references

Hornwort taxonomy and care recommendations cross-checked against the following authoritative references and our internal vendor + breeder database.

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