PlantFreshwaterBeginner

Amazon Frogbit

Limnobium laevigatum

Also known as: South American spongeplant, West Indian spongeplant

Fast-growing South American floater that gives surface-shy fish the shade they crave.

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About

Amazon frogbit (Limnobium laevigatum) is one of those floaters that just works in almost any freshwater setup, which is why you see it so often in community tanks, breeding setups, and low-tech planted aquariums alike. Native to South America and parts of the Caribbean, it grows naturally across a wide range of wetland habitats, including Colombia's river systems and floodplain lagoons, where it forms floating mats on calm or slow-moving water. In the aquarium it does the same thing, spreading across the surface with rosettes of rounded, bright green leaves and dangling roots that can grow surprisingly long. Those roots are a big part of its appeal: small fish and fry use them as cover, and surface-skimmers like hatchetfish or gouramis seem noticeably more relaxed under the shade the leaves provide. Growth rate is quick under decent light, so expect to thin it out regularly to keep it from blanketing the entire surface and starving lower plants of light. That said, the fast growth is also what makes it so satisfying. You can see real progress within days. It handles a wide range of water conditions and is a genuinely forgiving choice for newer planted tank keepers getting comfortable with live plants.

At a glance

Type: Plant
Water: Freshwater
Origin: Barrancabermeja; Núcleo Palmaceites; Distrito Regional de Manejo Integrado (DRMI) Laguna de Sonso, municipio de Guadalajara de Buga, Valle del Cauca, Colombia

Water parameters

Temperature: 64–82°F
pH: 5–8
Hardness: 4–20 dGH

Care guide

Plant frogbit at the water surface where it will naturally spread into floating mats. Prune regularly to prevent it from completely shading lower plants and blocking light penetration. Remove excess runners and rosettes every week or two depending on growth speed. The long dangling roots are excellent for fry and small fish shelter but can trap debris, so occasional gentle rinsing keeps them healthy. Fertilizer helps under low-light conditions, though most tanks with standard lighting won't require it. It tolerates poor water conditions well, making it ideal for cycling tanks or breeding setups. Remove any yellowing or damaged leaves promptly to maintain vigor.

Breeding

Amazon frogbit propagates by producing runners that develop new plantlets at their nodes. Simply allow runners to grow and separate new rosettes once they form roots. They'll establish quickly. No special conditions needed; faster growth under moderate to bright lighting accelerates runner production. Fragments can be replanted or left floating. Very reliable propagation makes this excellent for hobbyists wanting to propagate plants with minimal effort or experience.