(148) Alternanthera reineckii 'Cardinalis

Alternanthera reineckii 'Cardinalis' is a variety of the aquatic stem plant Alternanthera reineckii, often referred to by the cultivar name 'Cardinalis' or 'Telanthera Cardinalis'. It is known for its intense, deep red or purple coloration and is a popular choice for adding a bold color contrast to freshwater aquariums. 

• Lighting: Requires medium to high lighting. Insufficient light will cause the plant's color to fade and turn a duller green.
• CO2: While it can grow without supplemental CO2, injecting it will significantly enhance the plant's growth rate and intensify its red colors.
• Fertilization: A nutrient-rich substrate and regular dosing of iron-rich liquid fertilizers are essential for optimal health and color. Iron deficiency can cause the leaves to turn pale or yellow.
• Substrate: A soil-based substrate is recommended to provide the nutrients this root-feeding plant needs.
• Temperature: Prefers a temperature range of 72–82°F (22–28°C).
• Pruning: Regular trimming helps encourage bushier growth. The trimmed tops can be replanted to propagate the plant. 

• Midground or Background: Due to its upright growth, 'Cardinalis' is best placed in the midground or background of the aquarium, where its striking color can create a vibrant focal point and contrast well with green plants.
• Dutch-style aquariums: It is particularly well-suited for Dutch-style layouts, where it can be used to create eye-catching "plant streets". 

• Initial "melt": Like many aquatic plants, 'Cardinalis' is often grown emersed (out of water) by nurseries. When first submerged in an aquarium, it may lose some leaves while adapting to the new conditions. This is normal, and new submerged growth will emerge over time.
• Algae: The combination of high light and a nutrient-rich environment can make this plant a target for algae. Maintaining proper nutrient levels and lighting periods is crucial for preventing algae growth