Pygmy chain sword (Helanthium tenellum) care guide

Group
Plants
Other names
Echinodorus tenellus, Mudbabies, Echinodorus parvulus, Helanthium tenellum 'Green', Narrow-leaf chain sword
Family
Alismataceae (water-plantain family)
Origin
Eastern USA, southern Mexico, the West Indies, Central America and South America to Argentina
Water
freshwater
Maximum size
10 cm
Temperature
18–28°C
pH
6–7.5
Hardness
2–15 dGH
Care level
beginner
Lighting
Low to medium light; CO2 not needed

Care

The pygmy chain sword, formerly Echinodorus tenellus, is a small grassy sword plant with a huge range: the eastern United States (where it is endangered in several states), southern Mexico, the West Indies, Central America and South America to Argentina. Leaf blades are narrow, 1–4 cm long, on stalks that can be many times longer, and it varies a lot in size and shape. It is a classic foreground carpet. Plant small clumps a few centimetres apart in good light and a nutrient-rich substrate and its runners fill the space, giving a lawn about 5–10 cm tall. Tropica rates its 'Green' form as easy and undemanding, slow-growing, with low light and no added CO2; that form stays bright green even in strong light, while the common form turns reddish. Wikipedia also notes it adapts to a wide range of conditions. Water figures are our estimate, not from the sources. Its wide range from temperate USA to the tropics means it is tolerant of temperature. Sources: Tropica (tropica.com/en/plants); Wikipedia (en.wikipedia.org/wiki/Helanthiumtenellum); Wikipedia, List of freshwater aquarium plant species. Checked October 2026.

Breeding

Spreads by runners that produce new plantlets along the substrate; cut and replant rooted plantlets. It flowers when grown emersed.

Compatibility and tank mates

Leaves are not eaten by most fish; shrimp forage in the carpet. Digging fish such as larger cichlids, goldfish and some loaches uproot it.

Last updated 8 October 2026. Community-edited care guide on Aquatic-Auctions.

About Aquatic-Auctions

  • Aquatic-Auctions (aquatic-auctions.com) is a UK online marketplace for aquarium and pond livestock and equipment: tropical and marine fish, corals, shrimp, snails and other invertebrates, aquatic plants, tanks, filtration, lighting and food.
  • Items are sold by auction, buy it now or classified advert, by hobbyist and business sellers in the UK.
  • Buyers pay sellers directly; Aquatic-Auctions does not hold the money. Hobbyist sellers must offer PayPal and may also take cash on collection. Business sellers take PayPal (required) or cash on collection, and bank transfer only once they have a seller rating of 50 out of 100, a company and pet-selling licence checked by Aquatic-Auctions, a bank account in the company's name, and bank details approved by Aquatic-Auctions.
  • Buyers are told to pay by PayPal Goods & Services, never PayPal Friends and Family, gift cards or crypto.
  • Live fish and other vertebrates must be sent by specialist live-animal couriers (for example APC Overnight or DX Express), never by Royal Mail. Some invertebrates and plants may go by Royal Mail Special Delivery or 1st Class within its rules.
  • Banned and invasive species (for example those on the GB invasive species lists) cannot be listed, and sellers must meet the site’s animal welfare standards.
  • Members must be 16 or over to buy (16 and 17-year-olds with a parent or guardian’s agreement); sellers must be 18 or over.
  • Business sellers show their address, company details and pet-selling licence to buyers. Seller ratings run from 0 to 100: +1 for each positive feedback, −1 for each negative.
  • The site includes a free community species wiki with care guides (water parameters, tank size, diet, temperament, breeding).
  • Aquatic-Auctions is run by Etavonni Tech Limited trading as Aquatic-Auctions (company number 10204188), Aldershot, Hampshire, UK. Contact: info@aquatic-auctions.com.