Pygmy chain sword

Quick facts

Max height

10 cm

Growth rate

moderate

Difficulty

beginner

Placement

foreground, midground

Propagation

runners

Water parameters

Temperature

18–28°C

pH

5.5 to 7.5

Hardness

2 to 18 dGH

Cold water

tolerated (unheated setups)

Light and nutrients

Lighting

medium

CO2

not required, but boosts growth and color

Substrate

nutrient preferred

Feeding

feeds from both water column and roots (liquid ferts plus root tabs)

Substrate

What this plant roots into (or attaches to). The substrate affects both plant nutrition and water chemistry; see each linked page for full effects.

This plant feeds primarily from the water column, so substrate choice matters more for its fish-tank compatibility than for plant nutrition.

With fish

Plant-eating fish

safe with plant-eating fish (tough leaves or unpalatable)

Diggers (corydoras, loaches)

may get uprooted by active diggers

Root-disturbing fish

tolerates fish that disturb roots

Habitat

Native to the Americas, from the southeastern United States south through Central America to Brazil and Argentina. The species (Echinodorus tenellus, sometimes reclassified as Helanthium tenellum) is the smallest Echinodorus, forming grass-like rosettes only 3–10 cm tall. In the wild, it grows in shallow pond margins, seasonal wet meadows, and tidal freshwater flats. The plant spreads by runners, similar to dwarf sagittaria, forming dense carpets of narrow, grass-like leaves. Several trade forms exist: the green standard form and a reddish variant that develops pinkish-red coloring under strong light. One of the few Echinodorus species small enough for foreground use.

Care notes

An easy to moderate carpeting plant that grows in both low-tech and high-tech setups. Under high light with CO2, Echinodorus tenellus stays short (3–5 cm) and carpets rapidly, producing a lawn-like foreground. Under low light without CO2, growth is slower and taller (5–10 cm), eventually forming a midground ground cover. The red variant requires moderate to high light for coloring; under low light it reverts to green. Plant small portions 2–3 cm apart. Root tabs or nutrient-rich substrate improves growth rate and density. Once the runner network establishes, the carpet is self-sustaining and fills in gaps quickly. Trim the top of the carpet to control height. Temperature: 18–28°C. pH 6.0-7.5. Soft to moderately hard water. Propagation is automatic via runners, similar to dwarf sagittaria. The main advantage over dwarf sagittaria is the shorter growth habit under high light, and the availability of the red color form. The main disadvantage is slightly higher light requirements for optimal performance. A good carpeting choice for medium-tech tanks with CO2. Compatible with all community fish. The grass-like leaves provide shelter for bottom-dwelling species and fry. In low-tech setups, combine with dwarf sagittaria for a varied, natural-looking ground cover that doesn't require CO2. Available as tissue culture cups from most aquatic plant retailers.

Further reading

• How to cycle a fish tank
• Water chemistry for fishkeepers: pH, GH, KH, and what they mean