Dwarf hairgrass (Eleocharis acicularis): grower data
A grass-like plant that Tropica says thrives in almost all aquarium conditions and rates easy with low light and CO2 demand [1]. Its roots colonize the substrate to form a carpet 6–15 cm high, which can be cut back if it grows too tall [1].
Grower data
As published by Tropica Aquarium Plants[1]
- Light demand
- LowTropica: medium light demand is 0.5 W/L.
- CO2 demand
- LowTropica: medium need 6–14 mg/L; high approx. 15–25 mg/L.
- Growth rate
- Medium
- Difficulty
- Easy
| Type | not published by the source |
|---|---|
| Origin (grower) | Cosmopolitan |
| Height after two months | 10 - 15+ cm |
| Placement | foreground, midground[2] |
| Light (second grower) | Medium[2] |
| Care height (second grower) | 10–20 cm[2] |
| Water hardness (maximum) | Medium[2] |
Name and range
- Accepted name
- Eleocharis acicularis (L.) Roem. & Schult.[5]
- Family
- Cyperaceae
- Native range
- Afghanistan, Alabama, Alaska, Alberta, Altay, Arizona, Arkansas, Austria, Baltic States, Belarus, Belgium, Bolivia, British Columbia, Bulgaria and 116 more regions
- Introduced in
- Caroline Is., Gilbert Is.
- Records
- WCVP via GBIF and POWO
What the grower data says
Tropica describes Eleocharis acicularis as very common and says it thrives in almost all conditions in an aquarium, rating it easy with low light and CO2 demand and medium growth [1]. Aquasabi agrees on easy, medium growth and no need for added CO2, but rates light medium and gives a care height of 10–20 cm [2]. Both growers place it among the undemanding carpet plants, unlike Glossostigma or HC ‘Cuba’, which Tropica rates advanced.
The one condition Tropica does attach is space: an open area without shading from other plants is still preferable [1].
How it carpets
After planting, the roots start colonizing the surrounding substrate and the plant forms a carpet 6–15 cm high [1]. Tropica’s height rating, 10–15 cm or more after two months, sits within that range. If the carpet grows taller than wanted, Tropica says it can be carefully cut back to the preferred height [1]. Aquasabi lists it for the foreground, middle ground and nano tanks [2]; at 10–20 cm it makes a tall carpet compared with the 1–3 cm plants in the HC ‘Cuba’ group.
The ‘Mini’ form
Tropica also sells a much smaller hairgrass. Its catalog lists it as Eleocharis pusilla ‘Mini’ [3]. Tropica’s 2023 article on the same plant calls it Eleocharis acicularis ‘Mini’, describes it as an even smaller variety of dwarf hairgrass, says the first specimen came to Tropica from Tom Barr in the USA, and recommends moderate to strong lighting and CO2 injection for the best results [4]. The two names on Tropica’s own pages for one product show how unsettled hairgrass naming is in the trade.
The article’s care notes apply to hairgrass carpets in general: vacuum organic waste out of the carpet regularly to prevent algae and poor growth, and in the long term lift the whole mat, separate the healthiest plants and replant them [4].
Names and range
Eleocharis acicularis (L.) Roem. & Schult. is accepted in the World Checklist of Vascular Plants, in the sedge family Cyperaceae; Linnaeus first named it Scirpus acicularis [5]. Tropica’s origin field reads “Cosmopolitan” [1], and the checklist records a very wide native range of 130 regions across North America, Europe, Asia and parts of Central and South America [5, 6].
Questions
Is Eleocharis acicularis 'Mini' the same plant?
Tropica sells a separate, smaller form as Eleocharis pusilla 'Mini' [3]; its 2023 article calls that plant Eleocharis acicularis 'Mini' and recommends moderate to strong lighting and CO2 injection for it [4].
How do I keep a hairgrass carpet short?
Tropica says that if the carpet grows too tall it can be carefully cut back to the preferred height [1].
Similar plants
- Glossostigma elatinoides: grower data for a demanding carpetcarpeting, foregroundLight: HighCO2: HighAdvanced
- Monte Carlo (Micranthemum 'Monte Carlo'): grower data and historycarpeting, foregroundLight: MediumCO2: MediumMedium
- Sagittaria subulata (dwarf sagittaria): grower data and rangestolon, foreground / midgroundLight: LowCO2: MediumEasy
Related guides
- FertilizersRoot tabs and nutrient substrates: feeding through the rootsWhat Tropica and Seachem state about root capsules, tabs and nutrient substrates: contents, placement, how long they last, and where their own pages disagree.
- CO2 & lightWhat low, medium and high light and CO2 mean in grower plant dataTropica's light and CO2 ratings, the definitions behind them, the three different CO2 bands on its own pages, and how Aquasabi's categories line up.
Compare it with the other profiled plants in the plant parameter table.
Sources
- Eleocharis acicularis (plant details, 133TC). Tropica Aquarium Plants. Origin, growth, height, light, CO2 and difficulty (type blank); description: very common, thrives in almost all conditions, prefers open space, roots colonize to form a 6–15 cm carpet, can be cut back. Accessed October 12, 2026.
- Eleocharis acicularis (Aquarium Plant Profile). Aquasabi. Placement: nano aquarium, middle ground, foreground; easy; medium growth; medium light; hardness up to medium; 10–20 cm; CO2 not required. Accessed October 12, 2026.
- Eleocharis pusilla 'Mini' (plant details). Tropica Aquarium Plants. Catalog page for the smaller hairgrass sold as Eleocharis pusilla 'Mini'. Accessed October 12, 2026.
- Eleocharis acicularis 'Mini' (article by George Farmer, 28 February 2023). Tropica Aquarium Plants. A smaller variety first supplied to Tropica by Tom Barr; medium category; needs moderate to strong light and CO2; carpet care. Accessed October 12, 2026.
- Eleocharis acicularis (L.) Roem. & Schult.: World Checklist of Vascular Plants record (via GBIF). Royal Botanic Gardens, Kew; dataset published 2026-06-04, CC BY 4.0. Accepted name, family, synonyms, native and introduced range. Accessed October 12, 2026.
- Eleocharis acicularis: Plants of the World Online. Royal Botanic Gardens, Kew. Addressed by IPNI identifier 1169169-2; POWO displays the same WCVP data. Accessed October 12, 2026.