Amazon Sword Care Guide

Amazon swords are the big-leaf background plant that turned me into a planted tank person. I bought one as a $4 "background plant" from a local shop in 2021, planted it in a 29 gallon with cheap gravel and a stock LED, and watched it melt to nothing over a month — at which point I learned about emersed-to-submerged conversion, root feeding, and the absolute necessity of substrate nutrition. A year later, with the right setup, that same plant had filled half the tank and was putting out a flower stalk above the water line. Amazon swords are not hard once you understand what they actually need. They just need different things than epiphytes do.

Amazon sword (Echinodorus bleheri, also sold as E. amazonicus or E. grisebachii 'Bleherae') is a South American marsh plant that grows from a rosette crown with broad, bright green leaves. In nature it grows half-submerged at the edges of rivers and streams; in the aquarium it is fully submerged and grown as a background centrepiece. A mature plant reaches 50 to 60 cm tall and 40 cm wide — a single Amazon sword can dominate a 55 gallon tank, and they often do. This is the plant you buy when you want the tank to look "planted" without needing 15 species to fill the space.

Quick Stats

Tank Setup

Amazon swords need more light than Java fern or anubias, but not by much. Medium light — around 30 to 60 PAR at the substrate — is the sweet spot. Under low light they survive but grow slowly and produce small leaves; under high light they grow fast but become algae magnets if nutrients are not also plentiful. A standard planted tank LED on a 55 gallon for 8 hours a day is plenty. The mistake to avoid is putting an Amazon sword under a single stock fluorescent bulb in a deep tank — it will reach for the light, grow tall and sparse, and never fill out.

Substrate is where most Amazon sword keepers fail. The plant's root system is extensive and hungry — a mature plant has roots 20 to 30 cm long, all of them pulling nutrients from the substrate. Inert gravel or sand with no nutrient layer will starve the plant within months. You have two options: use a nutrient-rich substrate (Walstad soil layer capped with sand, or commercial planted substrate like Fluval Stratum, ADA Aquasoil, or Eco-Complete), or use inert substrate and supplement with root tabs every 2 to 3 months. Both work. The root tab approach is cheaper and easier for a beginner; the soil approach is more sustainable long-term. See the Walstad method guide if you want to go the soil route.

Water parameters are forgiving. Amazon swords tolerate pH from 6.5 to 7.5, hardness from soft to moderately hard, and temperatures from 22 to 28°C. They are not particular about flow but appreciate some water movement around the leaves to prevent debris buildup. Avoid strong direct flow that bends the leaves flat — they prefer gentle current.

Planting & Propagation

Planting an Amazon sword is straightforward but the crown placement matters. Remove the plant from its pot and gently tease away the rockwool from the roots under running water. Dig a shallow depression in the substrate, lower the plant in, spread the roots out, and backfill so the roots are buried but the crown (the point where the leaves emerge from the root system) sits right at substrate level. Do not bury the crown — a buried crown rots the same way a buried Java fern rhizome does. Do not leave the crown exposed above the substrate — the roots dry out and the plant lifts. Crown at substrate level, roots buried, leaves above.

Propagation is one of the more interesting things Amazon swords do. When a plant is well-established and growing vigorously, it occasionally sends up a long flower stalk that grows out of the water. This stalk develops small plantlets at nodes along its length — tiny Amazon swords with their own leaves and roots. You can let the plantlets grow on the stalk until they have 4 to 5 leaves and visible roots, then snap them off and plant them as new swords. The stalk will keep producing plantlets for weeks if you leave it. Alternatively, you can divide the crown of a mature plant by cutting it into pieces, each with leaves and roots — but the flower stalk method is easier and less risky.

Compatibility

Amazon swords are excellent community tank plants. Tetras, rasboras, danios, guppies, and livebearers do not damage them. Angelfish and discus use the broad leaves as spawning surfaces — a pair of angelfish will clean a sword leaf and lay eggs on it repeatedly. Gouramis and bettas appreciate the cover the big leaves provide near the surface. Corydoras and loaches root around the base of swords without harming the plant. Shrimp graze biofilm off the leaves.

The fish that damage Amazon swords are the plant-eaters and the diggers. Goldfish will nibble the leaves and shred the softer new growth; a large goldfish can defoliate a sword in days. Silver dollars and tinfoil barbs will eat Amazon sword leaves aggressively — do not combine them. Large cichlids (oscars, severums, parrots) may dig up the plant or shred the leaves; some keepers report success by planting swords in pots buried in the substrate to protect the roots. Plecos will rasp on sword leaves at night, leaving scrape marks, but rarely kill established plants.

One compatibility note: Amazon swords provide excellent cover for shy fish. A background cluster of swords in a 55 gallon creates shaded areas where shy corydoras, kuhli loaches, and dwarf cichlids feel secure. The leaf canopy also diffuses light, which helps fish that prefer dim conditions.

Common Problems

Transparent leaves: This is the #1 Amazon sword problem and it almost always indicates iron deficiency from nutrient-poor substrate. The leaves lose their opaque green colour and become translucent, especially the new growth. The fix is root tabs — push 2 to 3 tabs deep into the substrate around the plant's root zone. New growth will come in solid green within 2 to 4 weeks. Existing transparent leaves will not recover; trim them at the base. Repeat root tabs every 2 to 3 months indefinitely.

Melting after planting: Almost universal. Most Amazon swords sold in stores are grown emersed (out of water) and the emersed leaves melt off when first submerged. This is normal. The plant is not dying — the rhizome and roots are alive and new submerged-form leaves will emerge from the centre within 2 to 3 weeks. Trim the melting leaves so they do not rot and foul the water. By week 4 you should see new shorter, broader leaves growing from the crown.

Yellowing older leaves: Usually nitrogen deficiency, sometimes potassium. In a low-tech tank with fish, nitrogen is rarely the problem (fish waste supplies it). In a high-tech tank with CO2 and rapid growth, the plant may outpace nitrogen availability. The fix is a complete fertiliser that includes nitrogen and potassium, or for low-tech tanks, more root tabs and possibly a small amount of potassium sulphate.

Holes in leaves: Two distinct causes. Potassium deficiency produces small holes surrounded by yellow tissue, especially on older leaves — fix with potassium supplementation. Physical damage from fish (pleco rasping, goldfish nibbling, cichlid digging) produces jagged, irregular holes with no yellow halo. Distinguish between the two before treating.

Algae on the leaves: Amazon sword leaves are broad, slow to replace once the plant is mature, and prone to algae in high-light or high-nutrient tanks. Green spot algae is the most common. The fix is the usual — reduce light, increase water changes, add algae-eating inverts (Amano shrimp, nerite snails, otocinclus). Do not scrub the leaves; they bruise. Trim heavily algae-covered leaves at the base.

Frequently Asked Questions