Alternanthera reineckii

AR Magenta Growing & Care Guide

AR Magenta, or Alternanthera Reineckii, is the undisputed king of classic freshwater red plants. Native to South American riverbanks, it is celebrated for its spectacular leaf contrast, featuring dark olive-green tops and intense magenta-pink undersides. Highly durable, it serves as an elite midground bush, providing gorgeous architectural contrast in both low-tech and high-tech setups.

Lighting Moderate to High

Water Parameter Soft to Hard (pH 6.0-7.5)

Substrate Nutrient-rich Aquasoil / gravel

Water Temp 22°C - 28°C

Toxicity Pet Friendly (Non-toxic)

Botanical macro photography of AR Magenta (Alternanthera reineckii) - Plant AI care database

How to Identify AR Magenta

AR Magenta (Alternanthera reineckii) has key botanical markers. Recognizing these features is crucial for successful aquascaping and thriving growth.

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Visual Shape & Growth: Bushy vertical stems with striking leaves showing dark olive-green on top and deep magenta-purple underneath.
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Leaf Morphology: Lance-shaped leaves (approx. 1.5-3 inches long) with smooth margins, showing brilliant magenta/purple undersides.
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Root & Anchoring Structure: Massive, creeping vertical root network designed to absorb heavy substrate nutrients.

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Complete Cultivation & Spawning Guide

Follow our detailed scientific water parameters and care guides to keep your AR Magenta thriving.

pH: 6.0 - 7.5, GH: 3 - 15 dGH. Adapts well to soft or moderately hard water. High nitrates are absorbed rapidly.

Moderate. Beneficial for lush growth and rich red leaf development, though it can grow steadily in low-tech setups.

Moderate to high. High light intensity keeps the leaves compact and deepens the gorgeous reddish-purple marbling.

Propagate by cutting the top healthy stems and replanting. Cut mid-stems to force bushy lateral branching.

Requires heavy iron and micro-nutrient dosing to develop and maintain its iconic brilliant red color.

Requires rich aquasoil. Provide slow-release root tabs to feed its vertical root network.

Optimal temperature is 22°C to 28°C (71.6°F - 82.4°F). Sensitive to severe cold shocks below 15°C.

Requires steady water circulation. Good current prevents organic waste and algae spores from landing on broad leaves.

Its tough texture and bitter taste make it highly resistant to plant-eating fish. Safe for community setups.

Slow growth makes it susceptible to hair algae. Keep water clean and employ Amano shrimps or Nerite snails.

Best planted in the mid-ground. Space individual crowns 2 to 3 inches apart in the background.

Common Diseases & Treatment

Potassium Pinholes

Symptoms: Mature leaves develop tiny, dark-rimmed holes that grow larger, causing the leaf to drop.

Action: The definitive sign of potassium deficiency. Dose liquid potassium sulfate weekly.

Crown Rot (Suffocation)

Symptoms: Stems rot at the base and float away from the substrate.

Action: Caused by planting stems too deeply in compacted gravel. Pull stems slightly upward to keep the crown base clear.

Frequently Asked Questions

Why is the underside of my AR Magenta not red?

Under low light, the plant will fade to a dull bronze-green. Increase light intensity and dose iron weekly to restore its iconic magenta color.

Can I grow it without CO2?

Yes! Unlike many red plants, Alternanthera Reineckii can grow in low-tech tanks, though it will grow slower and be slightly less vibrant.

How do I propagate it?

Cut the stem below a node and replant the top section in the soil. The remaining bottom stem will sprout two new bushy shoots.

Does it need root tabs?

Yes. AR is a heavy root feeder. Regular root tab fertilization near the base will promote thick stems and broad, healthy leaves.