Elodea Najas

Quick facts

Identity

Also known as

Narrow-leaf Anacharis; Anacharis Najas

Synonyms

Elodea najas

Environment

Freshwater

Native to

Brazil, Paraguay, Uruguay, Argentina

Habitat

Slow-moving rivers, lakes and reservoirs, fully submerged, growing rooted or drifting in dense stands

Sourcing

Aquacultured

Conservation

Not Evaluated

Care

Care level

Easy

Growth form

Stem

Max height

4 – 16 in (10 – 41 cm)

Spread

2 in (5.1 cm)

Growth rate

Fast

Placement

Midground, Background

Water

Temperature

59 – 82 °F (15 – 28 °C)

pH

6.0 – 8.0

GH

2 – 20 dGH

dKH

0 – 20 dKH

Flow

Low-Moderate

Light

Medium

CO₂

Beneficial

Planting

Substrate

Any

Feeds from

Water column

Fertilizer needs

Medium

Colors

Green

Feeding & breeding

Propagation

Cuttings

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Care guide

Overview

Slender, whorled green leaves cover thin, fast-growing stems that can be rooted in substrate or left drifting near the surface. This South American native tolerates a broad range of temperature, hardness and light, making it suited to low-tech and high-light tanks alike. Brittle stems fragment and root readily, so trimming and disposal of cuttings need attention to avoid overrun.

Care

Narrow-leaf anacharis is one of the least demanding stem plants available, tolerating a wide swing in temperature, hardness and light intensity. It grows either rooted in substrate or left to drift near the surface, and adapts to low-tech tanks as readily as high-light CO2 setups. Under strong light expect weekly trimming, since the fine whorled foliage can pack on several centimeters of growth in a matter of days. Its brittle stems snap easily during handling, which is actually how it spreads in the wild and in the tank.

Planting & trimming

Plant stems loosely in bunches in the mid or background, leaving enough space between groups for water flow, or simply let clumps float near the surface. It anchors itself with fine white roots that sprout directly from the stem nodes, so no special substrate or root tabs are needed at planting. Trim the tops regularly to keep growth bushy and replant the cuttings or discard them, being mindful that this species is a regulated noxious weed in some regions such as California.

Fertilizing

This species feeds almost entirely from the water column rather than through roots, so liquid fertilizer or a light dosing of nitrogen, potassium and iron suits it better than root tabs. It is an efficient nutrient scavenger and often outcompetes algae for dissolved nitrate and phosphate in newly set up tanks. Pale, thin lower leaves that turn translucent and drop usually signal too little light rather than a nutrient shortage.

Propagation

Propagation is simply a matter of cutting healthy stem tops and replanting them, or allowing natural fragmentation to occur, since any node in contact with substrate or even floating in water will root and grow into an independent plant. This makes population control an active task in planted tanks, as trimmings left in the water column will readily continue growing.

Problems

Shaded lower leaves tend to yellow, go translucent and drop off, which is normal self-pruning rather than disease. Because the stems are so brittle, rough handling during transport or planting often leaves loose fragments floating in the tank, each capable of rooting into a new plant. Newly imported bunches should be quarantined and rinsed, since stock grown in outdoor Asian farms can carry snails or pesticide residue harmful to invertebrates.

Sources

1. Narrow leaf anacharis care: light, CO2 and placement · TankBud
2. Egeria najas (Elodea najas) Care Guide & Tank Setup | Atlarium
3. Egeria najas - Narrow-leaf Anacharis - Flowgrow Aquatic Plant Database
4. Egeria najas | Aquasabi - Aquascaping Shop

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