Red root floater
Phyllanthus fluitans
Water parameters
Light and nutrients
Substrate type: floating. Propagation: fragmentation.
Substrate compatibility
| Substrate | pH effect | Nutrient load |
|---|---|---|
| Bare bottom (no substrate) (Bare bottom) | n/a | none |
| Inert sand (Pool filter sand) | neutral / inert | none |
| Inert gravel (Aquarium gravel) | neutral / inert | none |
| Aquasoil (ADA Amazonia) | lowers pH | very high |
| Mineralized clay substrate (Seachem Fluorite) | neutral / inert | moderate |
| Dirted tank (mineralized topsoil) (DIY soil substrate) | slightly acidic | very high |
| Wood and rock mounts (Hardscape mount) | varies | none |
With fish
Origin and habitat
Native to Central and South America, found floating on the surface of slow-moving rivers, ponds, and marshes. The species (Phyllanthus fluitans) is a floating plant with small, round leaves (1–3 cm diameter) that develop vivid red coloring on the undersides and upper surfaces under strong light. The red coloring is the feature that distinguishes it from other small floaters like salvinia or duckweed and makes it popular as a decorative surface plant. The trailing roots are red to burgundy, adding to the ornamental appeal. Red root floater spreads by budding daughter plants connected by short stolons, forming loose mats on the water surface. Growth is slower than duckweed but faster than most submerged plants. The species was relatively unknown in the aquarium hobby until the 2010s, when it gained popularity through social media posts showcasing the vivid red coloring. It's now widely available from online aquatic plant retailers and hobbyist trades. P. fluitans is not considered invasive in most temperate regions because it's cold-sensitive (dies below about 15°C).
Outdoor pond use
- USDA zones
- 8–13 (winter low around -12°C or warmer)
Care notes
A decorative floating plant prized for its red coloring. Moderate to high light is essential for the red color; under low light, the leaves stay green and the plant loses its visual distinction from other floaters. Surface agitation from strong filter outflow pushes the plants around and damages roots; baffle the outflow or create a calm surface zone using airline tubing or a floating ring. The red color intensifies under iron-rich conditions; liquid iron supplementation in the water column makes a visible difference. Temperature: 20–30°C. pH 6.0-7.5. Prefers soft to moderately hard water. Low surface agitation and high light produce the most vivid red coloring. The plant absorbs nutrients from the water column through its roots, helping to reduce nitrate and phosphate. Growth rate is moderate; thin the population every 1-2 weeks to prevent complete surface coverage that blocks light to submerged plants. Propagation is automatic through daughter plants. Compatible with all fish. The trailing red roots provide shelter for fry and shrimp. Available from aquatic plant retailers and hobbyist trades.