Eichhornia natans

Species description

Care, breeding and tankmates

Plant profile

Placement

Midground

Due to its relentless drive to reach the surface, this plant is best positioned in the background of the aquarium. It requires significant vertical space to display its submerged leaves properly. It should be planted in small groupings, but space must be maintained between stems to prevent the lower portions from being completely shaded out. It is not recommended for shallow tanks.

Botanical form

Stem

Submerged, Eichhornia natans develops alternate, very narrow, linear green leaves along a somewhat fragile stem. The leaves are generally longer and narrower than other submerged Eichhornia species. When it breaches the surface, its morphology changes drastically, producing broader, rounded floating leaves typical of the genus, completely losing its submerged aesthetic.

Growth

Medium

This is an exceptionally fast-growing plant under high light and CO2 conditions. It will aggressively grow upwards, attempting to transition into its floating form. Because of this rapid vertical growth, it requires constant trimming to maintain a submerged presence. Its high metabolic rate makes it an excellent nutrient exporter.

Substrate

High

Eichhornia natans is a delicate floating or trailing plant that may sometimes send roots down to loosely anchor in the substrate if grown in shallow water. In most aquarium setups, it primarily relies on its trailing roots in the water column for nutrient absorption rather than deep substrate rooting. When planted, a soft, fine-grained substrate like aqua soil can help anchor any bottom-dwelling stems. However, its primary requirement is water column nutrition rather than a demanding soil bed.

Column fertilization

Recommended

Liquid fertilization is absolutely mandatory for this species. It absorbs the vast majority of its required nutrients directly through its submerged leaves from the water column. A daily dosing regimen of a high-quality, comprehensive liquid fertilizer is often necessary to keep up with its aggressive growth rate. Deficiencies will manifest quickly in the new growth.

Root fertilization

None

While primarily reliant on the water column, planting E. natans in a nutrient-rich substrate like aquasoil is beneficial. A strong root system helps anchor the long, buoyant stems securely against the water flow. However, root feeding is secondary, and the plant will perish if column fertilization is neglected.

Trimming

Regular

To maintain it as a submerged stem plant, aggressive and frequent topping is required. The best practice is to uproot the entire stem, cut off and discard the leafless or unsightly lower portion, and replant the vibrant top cutting. Allowing it to reach the surface will cause the lower submerged leaves to die off as the plant transitions to its floating state.

Propagation

Cuttings

Propagation is easily achieved by taking top cuttings from healthy stems and replanting them. It may also occasionally produce lateral shoots, which can be separated and planted. Ensure that all new cuttings have unhindered access to strong light to promote rapid rooting and acclimatization. Strong initial growth is essential.

Sensitivity

Moderate

Eichhornia natans is exceptionally sensitive to shading and will rapidly lose its lower leaves if they do not receive direct light. It is also completely intolerant of low CO2 levels, which will cause immediate stunted growth and melting. The stems are quite brittle and must be handled carefully. It does not respond well to abrupt changes in water chemistry.

Layout role

Midground

In aquascaping, it is used primarily as a background stem plant to provide a unique, fine-leaved texture that contrasts beautifully with broader foliage. Its rapid growth and vertical lines make it suitable for large nature aquariums or Dutch-style setups. However, its demanding nature and need for constant trimming mean it is best left to experienced aquascapers.