Common Duckweed (Lemna minor)

Common Duckweed (Lemna minor) is one of the world's smallest flowering plants, forming a bright vivid-green film across the water surface that spreads rapidly in nutrient-rich water. It is an exceptional nutrient absorber and natural live food source for surface-feeding fish including goldfish, koi, and mollies. Its rapid growth makes it one of the most effective natural nitrate and phosphate export plants available.

Simply add a small portion to the water surface — it will spread naturally. Requires no substrate, fertilizer, or CO2. Remove excess regularly to prevent shading of submerged plants and allow light penetration. An excellent indicator plant — yellowing suggests nutrient deficiency. Note: classified as invasive in some jurisdictions; do not release into natural waterways.