Cryptocoryne thwaitesii

Cryptocoryne thwaitesii is a moderate-sized species from Sri Lanka with narrow to lance-shaped leaves that range from dark green to brownish-green, sometimes with subtle surface hammering or bullation. It is less commonly offered than the mainstream Sri Lankan Crypts, making it a desirable find for enthusiasts. It adapts well to aquarium conditions and is tolerant of soft, slightly acidic water as well as moderately hard, neutral conditions. Growth is slow and patient, and it spreads via underground runners in a well-established, nutrient-rich substrate.

Light: Low to medium (15–40 PAR); a true low-light species. CO2: Not required; grows without injection. Fertiliser: Root tabs every 4 months; minimal liquid fertiliser is adequate. Planting: Midground; plant in groups of 3–5 rosettes 4 cm apart; keep crown just above substrate. Growth: Slow; reaches 15–25 cm; spreads via runners over time; very little maintenance needed.