Amazon Frogbit

Amazon frogbit is the floating plant most aquarists meet first, and for good reason — it grows fast enough to outcompete algae while its roots stay neat rather than tangling into a mat. Each thick, glossy oval leaf sits at the surface on a short stem, buoyed by a spongy cushion of aerenchyma on its underside.

The roots hang straight down, reaching 15 to 30 cm, and provide shelter for fry and shrimp. Unlike duckweed, the individual plants are large enough to remove by hand without leaving fragments behind. The growth rate under moderate light is very fast — a handful of plants can cover the surface of a 60 cm tank in a few weeks.

Temperature from 20 to 27 °C and pH between 5 and 8 covers most aquarium setups. CO₂ injection is unnecessary; the plant absorbs CO₂ from the air above the water surface. Strong flow should be avoided — the roots and leaves are delicate, and constant submersion from a filter outlet will cause the leaves to rot.

Thinning is regular maintenance: if left unchecked it covers the entire surface and blocks light from plants below. Propagation is by stolons that produce daughter plants. It can grow emersed and is half-hardy, surviving mild winters outdoors in some climates.