Alternanthera reineckii

Scientific name: Alternanthera reineckii

Family: Amaranthaceae

Usual maximum size in aquariums: 25 - 50 cm (9.84 - 19.69 inch)

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Recommended pH range for the species: 6.2 - 7.1

Recommended water hardness (dGH): 4 - 12°N (71.43 - 214.29ppm)

0°C 32°F30°C 86°F

Recommended temperature: 23 - 30 °C (73.4 - 86°F)

Reproduction of the plant: Cuttings

Origin (in the wild): South America

How fast these plants grow: Slow

Recommended substrate: Fine gravel

Demands on lighting: Bright

Ideal placement in a fish tank: Middle

Common Names

Magenta Water Hedge

Origin

Alternanthera reineckii originates from South America, particularly in the Amazon Basin, where it grows in slow-moving rivers, flooded banks, and wetland regions. It can adapt to both submerged and emersed conditions depending on the season, making it a resilient and flexible aquatic plant.

Quick Overview

• Ideal For: Aquariums, paludariums, ponds
• Difficulty Level: Medium
• CO₂ Requirements: Beneficial but not essential

Growing Conditions

Alternanthera reineckii thrives when fully submerged in aquariums but can also grow emersed in humid paludarium environments. Bright lighting is essential to support its rich red coloration and prevent lower leaf drop. Low light levels result in slower growth and pale coloration.

For best results, plant it in a nutrient-rich fine gravel or sand substrate. Supplementation with iron and potassium, either via root tabs or liquid fertilizers, helps maintain its vibrant color and compact form. While CO₂ injection is not required, it significantly enhances growth and coloration under high light.

Planting Area

This plant is suitable for the midground or background in larger aquariums, and it can serve as a colorful focal point in smaller tanks. When planted in groups, it creates a vivid, bushy effect. Ensure adequate spacing to allow light penetration and water flow between stems.

Propagation

Propagation is easy via stem cuttings. Cut healthy stems just above a leaf node and replant them directly into the substrate. Ensure each cutting has several leaves, and press gently to anchor it. Regular trimming encourages bushier growth and prevents legginess.

Difficulty

This species is of medium difficulty. It requires stable water conditions, bright lighting, and consistent nutrient supplementation. When these needs are met, it rewards aquarists with vibrant color and healthy growth. Suitable for intermediate hobbyists or beginners ready to advance to moderate plant care.

Short Description

Alternanthera reineckii is a colorful, slow-growing stem plant with rich red to magenta leaves that create a striking contrast in aquascapes. It adds visual depth, especially in Dutch-style layouts or nature-style tanks that emphasize color layering. While it tolerates emersed growth, it shows its best coloration and form when submerged under proper conditions.

Lighting Requirements

Bright light is critical for this plant’s health and color. Under fluorescent lighting, aim for 0.5–1 watt per liter (2–4 watts per gallon), or 30–40 lumens per liter (120–160 lumens per gallon) with LEDs. Provide at least 8–10 hours of lighting daily. In high-light setups, supplemental CO₂ further boosts vitality and coloration.

Potential Issues

• Yellowing or Browning Leaves: Usually caused by low light or iron deficiency. Address with stronger lighting and iron-rich fertilizers.
• Poor Growth: Caused by inadequate lighting or lack of nutrients. Ensure balanced fertilization and stable parameters.
• Lower Leaf Drop: Common under insufficient light. Increase intensity and ensure CO₂ availability if possible.
• Temperature Sensitivity: Grows best above 23 °C (73.4 °F). Cooler water slows growth and can stress the plant.

Overall Appeal

Alternanthera reineckii is a favorite among aquascapers for its bold red tones and adaptable growth. It enhances both beginner and expert layouts with contrast and height variation. When provided with bright lighting, steady nutrients, and optionally CO₂, it becomes a lasting highlight in any aquascape. Its manageable growth and decorative potential make it a rewarding species in diverse aquatic environments.