Amazon Frogbit
Amazon frogbit is a floating plant that looks like a scatter of tiny green lily pads on the surface, trailing long feathery roots into the water below.
Last reviewed: October 2026
AI illustration Overview
Amazon frogbit is a floating plant that looks like a scatter of tiny green lily pads on the surface, trailing long feathery roots into the water below. It shades the tank, soaks up nutrients fast, and gives surface-dwellers and fry cover - all with no substrate and no CO2. (Limnobium laevigatum.)
Origin & Natural Habitat
Still and slow waters of Central and South America.
Appearance
Rosettes of round, glossy green pads a few centimetres across floating on the surface, with dense trailing roots beneath.
Why People Grow It - Qualities & Benefits
- Fast floating nutrient export
- Shades the tank and fights algae
- Cover and food refuge for fry
- No planting needed
Care
Light: Moderate to high from above; as a floater it gets the brightest light in the tank.
Water: 18-28°C, pH 6.0-7.5; adaptable.
Substrate: None - it floats. Trailing roots feed from the water column.
CO₂ & feeding: Not needed; floaters take CO2 from the air.
Placement: Surface - corral it with a floating ring or airline so it does not cover everything.
Extra: Keep water off the pads and keep the surface moving gently but not splashing - wet, splashed leaves rot and melt. A low water level under the lid, or a surface skimmer that is not too strong, keeps the tops dry.
Extra: Amazon frogbit (Limnobium laevigatum) is regulated in parts of the US - it is a Class A noxious weed on the Washington State quarantine list, where it is illegal to buy, sell or transport it, and it carries an A rating from the California Department of Food and Agriculture. Check your local rules before buying, keep it contained, and dispose of it dry in the bin. Never put it in a pond, ditch or waterway.
Propagation
Splits into daughter rosettes on its own; just remove excess to control it.
Common Problems & Pests
Melting from overhead condensation and splashing; grows fast enough to block light to plants below - thin it regularly.
Toxicity & Safety
Not on the ASPCA lists. The ASPCA Animal Poison Control Center's plant lists for cats and dogs have no entry for this plant, and we have no other checked source either way. Never release floaters outdoors - many are invasive. Confirm it is legal where you live. If a pet chews it and seems unwell, call your vet or a pet poison helpline.
Best Suited For
- Nutrient export and shade
- Fry and shrimp tanks
- Blackwater and low-light aquascapes
- Beginners in regions where it is legal
FAQ
Is Amazon frogbit legal to own?
It depends on where you live. In Washington State it is a Class A noxious weed on the quarantine list, so buying, selling or transporting it is illegal, and California rates it as an A-list pest. Check your local regulations before buying, and never release it.
Why are my frogbit leaves rotting?
Usually water sitting on the pads - from condensation dripping off the lid or filter splash. Keep the tops dry and the surface calm.
It's taking over the surface - is that a problem?
It can shade out plants below. Scoop out the excess regularly; bin it dry, never release it to the wild.
Gear for growing amazon frogbit
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