Rotala macrandra Giant Red

Rotala macrandra is native to India and is considered the pinnacle of red stem plants in the aquarium hobby. Its large, broadly oval leaves have a distinctly ruffled margin and achieve a deep crimson to wine-red colour under optimal conditions of intense light, CO2 injection, and rich micronutrient dosing. It is one of the more demanding stem plants in cultivation, requiring consistently high light and CO2 as well as pristine water chemistry. Despite its challenges, the visual payoff is unmatched in the red-plant category.

Light: High (80–120 PAR); very high light is essential for red colour; low light causes etiolation. CO2: Required at 25–40 mg/L; without CO2 the plant declines rapidly. Fertiliser: Very high iron and trace elements; dose daily; ensure no nitrogen or phosphorus deficiency. Planting: Background groups of 3–5 stems spaced 3 cm apart; trim every 1–2 weeks. Growth: Moderate; 30–60 cm; re-plant trimmed tops for denser effect.