Echinodorus tenellus

A carpet you can actually grow without CO₂. Pygmy Chain Sword throws narrow, grass-like leaves a few centimetres tall and then sends runners sideways across the substrate, each one rooting and putting up a new plant. Left to it, a handful of plants becomes a continuous lawn. It is the one foreground carpet available to a low-tech Indian tank, and it is why this unremarkable-looking little plant is worth more attention than it usually gets.

Under strong light it stays short, dense and often takes on a bronze-red flush at the leaf tips. Under moderate light it grows taller and looser, more meadow than lawn, which is a perfectly good look in its own right. Either way it is a sword underneath — tough, tolerant of hard alkaline water, and content at Indian room temperature with no equipment at all.

Care Snapshot

Scientific name	Echinodorus tenellus (accepted: Helanthium tenellum)
Also known as	Pygmy Chain Sword, Micro Sword, Narrow-leaf Chain Sword
Family	Alismataceae
Origin	Nursery-propagated; the genus ranges through the Americas
Plant type	Small rosette, spreads by runners
Placement	Foreground carpet, or mid-ground in nano tanks
Height	3–6 cm in strong light; 10–15 cm in weaker light
Growth rate	Moderate to fast once established
Lighting	Medium to high — determines whether it carpets
CO2	Not required; produces a denser carpet with it
Temperature	22–29 °C
pH	6.0–8.0 — wide tolerance
Hardness	Soft to hard — handles Indian tap water well
Substrate	Fine sand or aquasoil, 3–5 cm deep
Fertilisation	Root tabs in inert substrate; it is a root feeder
Difficulty	Easy to moderate — easy to grow, harder to carpet

Compared With The Other Carpet Plants

Planting It

• Separate the clump into small portions. Tissue-cultured or potted stock arrives as a dense mass. Wash off any gel or rockwool and divide it into pieces of two or three plantlets each — far more ground covered from the same purchase.
• Plant portions 3–5 cm apart across the area you want covered. The runners close the gaps themselves; planting tight just wastes plants.
• Bury the roots, keep the crowns clear. Push the roots in with tweezers and leave the base of the leaves sitting at the substrate surface. Buried crowns rot.
• Fine substrate only. The roots are delicate and shallow. Coarse gravel makes it hard to anchor and hard to spread.
• Root tabs under the carpet area. Spread a few across the planting zone rather than clustering them, and top up every few months.
• Expect emersed-grown stock to convert. Nursery plants raised out of water shed their original leaves and regrow shorter submersed ones. The first few weeks look disappointing; this is normal.

Keeping The Carpet Healthy

A mature carpet thickens into layers, and the lower layer eventually loses light and dies off. Left long enough, the whole mat detaches from the substrate in sheets. Prevent it by thinning every few months: pull out sections, trim the carpet back with scissors, and let the runners refill. This is the maintenance job that keeps a chain sword lawn going for years.

Keep detritus off it. Fine grassy foliage traps mulm and uneaten food, which encourages algae and smothers the base. A gentle siphon over the carpet at each water change is enough.

Propagation

It propagates itself. Runners travel horizontally just under or along the substrate, putting up a new rosette every few centimetres — a chain of plants, which is where the name comes from. To move growth elsewhere, snip a runner between two established plantlets and replant the piece with its roots buried and crown clear. Because it multiplies this freely, buying a modest quantity and letting it spread costs far less than buying enough to cover the area outright.

What It Pairs With

Shrimp-safe and snail-safe, and the dense grassy base is excellent cover for shrimplets and fry — worth considering if you are breeding Neocaridina or small fish. Corydoras and loaches forage happily through it without much damage once it has rooted, though they will unsettle newly planted portions, so let it establish for a few weeks first. Underneath a Cryptocoryne mid-ground and a sword at the back, it completes a low-tech layout with no stem plants and no CO₂ anywhere in it.

Growing It In Indian Conditions

• This is the realistic carpet option for an Indian tank. Hard alkaline tap water, room temperature, no CO₂ — the conditions that rule out Monte Carlo, dwarf hairgrass and HC for most keepers here. Light is the only thing you need to invest in.
• Summer is survivable. Comfortable to around 29 °C. Growth slows in peak heat and the carpet may thin, but it recovers once temperatures drop rather than melting away.
• No heater needed anywhere in India for most of the year.
• Spend on light and root tabs, not on quantity. Buying a large amount into a dim tank gives you tall sparse grass. Buying a modest amount into a well-lit, root-fed tank gives you a lawn within a few months, for less money.