Ceratophyllum submersum Soft Hornwort

Ceratophyllum submersum is closely related to the common Hornwort (C. demersum) but has softer, less brittle leaves and tolerates warmer temperatures. Being rootless, it absorbs nutrients directly from the water column, making it one of the most effective biological filters in the planted aquarium. It requires no substrate and can be left floating or lightly anchored. Its rapid, undemanding growth makes it virtually foolproof for any aquarium setup.

Light: Low to medium (10–50 PAR); very adaptable; grows even under basic fluorescent lighting. CO2: Not required; absorbs dissolved CO2 from water naturally. Fertiliser: Minimal fertilisation needed; absorbs nutrients from water column effectively. Planting: Float freely or anchor loosely in background; thin regularly to prevent shading. Growth: Very fast; 20–100 cm; thin or remove excess growth every 1–2 weeks.