Alternanthera reineckii Rosaefolia

Quick facts

Max height

40 cm

Growth rate

moderate

Difficulty

intermediate

Placement

midground, background

Propagation

stem cuttings

Water parameters

Temperature

20–28°C

pH

5.5 to 7.5

Hardness

2 to 15 dGH

Light and nutrients

Lighting

high

CO2

not required, but boosts growth and color

Substrate

nutrient preferred

Feeding

feeds from both water column and roots (liquid ferts plus root tabs)

Substrate

What this plant roots into (or attaches to). The substrate affects both plant nutrition and water chemistry; see each linked page for full effects.

This plant feeds primarily from the water column, so substrate choice matters more for its fish-tank compatibility than for plant nutrition.

With fish

Plant-eating fish

safe with plant-eating fish (tough leaves or unpalatable)

Diggers (corydoras, loaches)

fine - root system or attachment style handles it

Root-disturbing fish

tolerates fish that disturb roots

Habitat

Cultivar of Alternanthera reineckii originally selected in aquarium nurseries for its narrower, more intensely pink-purple leaves than the standard form. The wild parent species is native to South American floodplains. 'Rosaefolia' has become one of the most popular named Alternanthera cultivars in the aquascaping hobby, commonly available from tissue culture. The leaves are lanceolate, pointed, and develop vivid magenta to deep pink coloring under high light with CO2. Emersed (farm-grown) specimens look very different from the submerged form: green leaves with reddish undersides. The transition to submerged growth takes 2-4 weeks, during which the plant may drop some emersed leaves before producing new submerged foliage.

Care notes

Similar requirements to the standard A. reineckii but considered slightly more demanding in terms of light and CO2. Strong lighting is essential; this cultivar loses its pink coloration faster under low light than the standard form, reverting to dull olive-brown within a few weeks. CO2 injection makes a significant difference: with CO2 at 20-30 ppm and high light (70+ PAR at substrate), the leaves develop the vivid magenta-pink that makes this plant desirable. Without CO2, expect muted pinkish-brown at best, which may not be worth the effort. Iron supplementation (either through root tabs or water column dosing) is important for red and pink pigment production; iron-deficient plants lose color starting at the newest leaves, which emerge pale green. Trim and replant tops every 3-4 weeks to prevent the lower stem from becoming bare and leggy. The cut lower stem produces side shoots within 1-2 weeks, creating a bushier growth pattern over time. Moderate nitrate levels (10-20 ppm) seem to produce the best coloring; very high nitrate (above 30 ppm) can push red plants toward green. Propagation is by stem cuttings: cut the top 10–15 cm and replant. Plant in groups of 5+ stems for visual impact. In aquascaping, Rosaefolia is commonly used as a midground accent color, positioned where it catches strong direct light from above.

Further reading

• How to cycle a fish tank
• Water chemistry for fishkeepers: pH, GH, KH, and what they mean