Juncus repens
Also sold as Juncus · Lesser creeping rush
Synonyms Creeping rush
Juncus repens is a rosette plant for the midground, growing to about 20 cm (7.9 in) at a moderate pace. It wants 68–82°F (20–28°C), low light and CO₂ if you have it, and counts as an easy plant to keep alive.
At a glance
| Type | Rosette plant |
|---|---|
| Light | LowThe least light it survives in, not the light it looks best in. |
| CO₂ | RecommendedWhether it survives without added CO₂ — not whether CO₂ would help it grow faster. |
| Difficulty | Easy |
| Temperature | 68–82°F (20–28°C) |
| Max height | 20 cm (7.9 in)Grown submersed, left to mature, never trimmed. |
| Growth rate | Moderate |
| Placement | planted in the midground |
| pH | 6–7.5 |
Before it goes in
- Juncus repens lives under a plain low-light LED — it does not need a planted-tank lamp to survive.
- CO₂ is not required, but without it expect slow growth and a thinner result.
- It only colours up under strong light with CO₂; in a low-tech tank it stays green.
- At about 20 cm (7.9 in) it belongs behind everything shorter — planted at the front it hides the rest of the scape and shades it.
- Its leaves are medium: Goldfish, Electric Yellow Lab and Colombian Ramshorn Snail will eat it.
Can it grow without CO₂?
Yes, but slowly. Juncus repens is listed as CO₂-recommended, not CO₂-required: without injection it survives and grows, it just takes far longer to fill in.
How much light does it need?
Low light is enough — and that is the survival line, not the “it looks better” line. Colour is a separate question: it only turns red under strong light with CO₂.
How big does it get?
About 20 cm (7.9 in) tall when it is mature and untrimmed, growing at a moderate pace, after roughly 3 weeks to root in.
Will my fish eat it?
Its leaves are medium, so some will: Goldfish, Electric Yellow Lab and Colombian Ramshorn Snail.
What it goes with
- Plants that run on the same light and CO₂, so they can share a tank without one of them being the odd one out: Hygrophila corymbosa 'Siamensis', Water Sprite, Anubias nana 'Petite' and Frogbit.
- Animals that share its temperature range and will not eat or uproot it: Betta, Cherry Shrimp, Angelfish and Bristlenose Pleco.
Often compared with
| Juncus repens | Echinodorus 'Aquartica' | Echinodorus 'Reni' | |
|---|---|---|---|
| Light | Low | Medium | Low |
| CO₂ | Recommended | Not needed | Not needed |
| Max height | 20 cm | 20 cm | 20 cm |
| Difficulty | Easy | Medium | Easy |
More plants
Sources (2) · checked Sep 2026
- Difficultybuceplant.com
- Difficultytropica.com