Najas flexilis

Najas flexilis is native to North America and Europe, inhabiting cool, clear lakes and streams with soft to moderately hard water. It produces extremely fine, flexible leaves on delicate, freely branching stems, forming soft, cloud-like masses with a distinctly feathery texture. In the aquarium it functions primarily as a spawning medium and refuge plant — its fine texture traps eggs safely while providing shelter for fry and invertebrates. It prefers cooler water than tropical Najas species, performing best in temperate and subtropical tanks. Growth is fast under low to medium light, and it spreads readily from stem fragments scattered through the aquarium.

Light: Low to medium (15–50 PAR); thrives under minimal lighting in cool tanks. CO2: Not required; grows on ambient dissolved CO2 in cool, clear water. Fertilisation: Minimal — very light feeder; dilute all-in-one liquid fertiliser every 3 weeks. Placement: Floating loosely or anchored loosely in midground as spawning media and shelter cover. Propagation: Stem fragments establish freely; simply scatter pieces throughout the aquarium.