Alternanthera reineckii (Alternanthera reineckii)
Live plants are the backbone of a healthy, visually striking freshwater aquarium. They improve water quality, provide shelter for fish, and elevate aquascaping from a simple tank setup into a living work of art. Among the many colorful aquatic plants available to hobbyists, Alternanthera reineckii stands out as one of the most popular red plants in the aquascaping world.
Known for its deep red to purple hues and bold leaf structure, Alternanthera reineckii adds dramatic contrast to green-dominated aquascapes. While it is slightly more demanding than beginner plants, it rewards attentive aquarists with vibrant color and lush growth, making it a favorite in high-tech planted tanks and competition layouts.
Plant Profile
Scientific and Common Names
Scientific name: Alternanthera reineckii
Common names: Scarlet Temple Plant, Red Alternanthera
Natural Habitat and Origin
Alternanthera reineckii originates from South America, where it grows along riverbanks, floodplains, and marshy areas. In the wild, it often experiences seasonal flooding, which allows it to grow both submerged and emersed. This adaptability makes it suitable for aquariums, paludariums, and even riparium-style setups.
Plant Type
This species is a rooted stem plant. It absorbs nutrients primarily through its roots but also benefits from nutrients in the water column.
Growth Pattern
Alternanthera reineckii grows upright with sturdy stems and opposite leaves. When trimmed regularly, it can branch and form dense bushes. Without trimming, it tends to grow tall and leggy, especially under insufficient lighting.
Aquascaping Placement
Due to its height and bold coloration, Alternanthera reineckii is best suited for the midground to background of the aquarium. In larger tanks, it can be used as a background plant, while in smaller layouts it often shines as a midground focal point.
Care Guide
Lighting Requirements
Lighting is one of the most critical factors in successfully growing Alternanthera reineckii. It thrives under moderate to high-intensity lighting. Strong lighting is essential to maintain its red coloration—under low light, leaves often turn green or brown.
A full-spectrum LED designed for planted aquariums is ideal. Aim for 8–10 hours of consistent lighting per day. Excessive lighting without proper nutrients, however, can lead to algae issues.
For a deeper dive into proper plant lighting, see this aquarium lighting guide.
Water Parameters
Alternanthera reineckii prefers stable, tropical freshwater conditions:
Temperature: 22–28°C (72–82°F)
pH: 5.5–7.5
Hardness: Soft to moderately hard water
While it can tolerate a range of conditions, consistent parameters are far more important than chasing exact numbers.
Substrate Preferences
A nutrient-rich substrate is highly recommended. Aquasoils designed for planted tanks provide the best results, though fine gravel or sand supplemented with root tabs can also work.
If you are still deciding on a substrate, this guide on choosing the right aquarium substrate is a helpful resource.
Fertilization and CO₂
Alternanthera reineckii is a heavy feeder. Regular fertilization is essential to maintain healthy growth and vivid color. A complete liquid fertilizer containing iron is particularly important, as iron deficiency often results in pale or yellowing leaves.
While not strictly required, CO₂ injection significantly improves growth rate, leaf size, and color intensity. In high-tech planted tanks, CO₂ is strongly recommended for the best results.
Learn more about the benefits of carbon supplementation in this article on CO₂ in planted aquariums.
Trimming, Propagation, and Growth Rate
Alternanthera reineckii has a moderate growth rate under optimal conditions. Regular trimming encourages bushier growth and prevents the plant from shading itself.
Propagation is simple: cut healthy stems and replant them directly into the substrate. New roots typically develop within a week or two.
Aquascaping Tips
Using Alternanthera reineckii as a Focal Point
The rich red coloration of Alternanthera reineckii makes it ideal for creating focal points. It contrasts beautifully against green plants like Cryptocoryne, Vallisneria, or Java Fern, drawing the viewer’s eye toward specific areas of the layout.
Compatibility with Hardscape
This plant pairs exceptionally well with natural hardscape materials such as driftwood and stone. Dark rocks enhance its red tones, while wood creates a more organic, riverbank-inspired appearance.
For inspiration, explore aquarium-safe wood options and safe rock choices.
Ideal Tank Sizes and Layout Styles
Alternanthera reineckii performs best in tanks of 20 gallons or larger, where stable conditions are easier to maintain. It is commonly used in Dutch-style aquascapes, Nature Aquariums, and modern high-contrast layouts.
If you’re planning a new setup, this step-by-step aquarium setup checklist can help you get started.
Tank Mates and Compatibility
Compatible Fish and Invertebrates
Alternanthera reineckii is compatible with most peaceful community fish. Small tetras, rasboras, gouramis, and dwarf cichlids coexist well without damaging the plant.
Shrimp species such as cherry shrimp and Amano shrimp are excellent companions, as they help keep algae under control without harming the leaves.
Species to Avoid
Avoid housing Alternanthera reineckii with known plant-eaters such as large goldfish, silver dollars, or aggressive cichlids that may uproot or shred stems.
Common Problems and Solutions
Loss of Red Color
The most common issue is fading or green coloration. This is usually caused by insufficient lighting, low iron levels, or lack of CO₂. Increasing light intensity and ensuring proper fertilization typically resolves the problem.
Melting Leaves
Leaf melt often occurs after planting, especially when transitioning from emersed-grown specimens. This is normal, and new submerged leaves usually appear within a few weeks if conditions are stable.
Algae Growth
Excess light combined with poor nutrient balance can lead to algae on leaves. Maintaining proper fertilization and consistent maintenance routines helps prevent outbreaks. For natural control methods, see this algae control guide.
Frequently Asked Questions
Is Alternanthera reineckii suitable for beginners?
It is best suited for intermediate aquarists. Beginners can grow it successfully, but it requires stronger lighting and regular fertilization compared to beginner plants.
Does Alternanthera reineckii need CO₂?
CO₂ is not mandatory, but it greatly improves growth, coloration, and overall plant health.
How fast does Alternanthera reineckii grow?
Growth is moderate under optimal conditions. With high light, nutrients, and CO₂, it can require trimming every few weeks.
Conclusion
Alternanthera reineckii is a stunning addition to freshwater aquariums, offering bold color and strong visual impact. While it demands more attention than beginner plants, its beauty and versatility make it well worth the effort.
By providing proper lighting, nutrient-rich substrate, and consistent care, aquarists can enjoy lush, red foliage that transforms their aquarium into a vibrant underwater landscape. Whether used as a focal point or a supporting accent, Alternanthera reineckii is a plant that elevates any planted tank and inspires creativity in aquascaping.
For more plant-focused inspiration and care guides, explore the full aquarium plants section on Fishy Friends.
