Red root floaters: the red surface jewel
Phyllanthus fluitans
Small floating leaves that blush deep red under strong light.
Where it comes from
Phyllanthus fluitans drifts on quiet tropical waters of the Amazon basin in South America. In shade it is an unremarkable green, but under strong sun the leaves and roots flush a rich red — an adaptation to protect the plant from intense light that aquascapers prize.
What to expect
Each plant is a small rosette of rounded, slightly cupped leaves rarely more than a centimetre or two across, with a tuft of roots below. Under bright light the leaf undersides and the roots turn deep crimson, giving the plant its name and a splash of colour few other floaters can match.
How to keep it
Getting the red is the whole game, and it comes down to light. Weak lighting gives flat green plants; strong lighting, plus available iron, brings out the crimson. Unlike most floaters it is fussier — it resents disturbance and a wet, humid surface — so it earns a Medium rating.
| Parameter | Value |
|---|---|
| Lighting | Medium to high — red colour needs strong light |
| CO2 | Not required; beneficial |
| Temperature | 22–28 °C |
| pH | 6.0–7.5 |
| Hardness | Soft to moderate |
| Fertiliser | Iron drives the red pigment |
| Substrate | None — floats |
| Growth rate | Moderate to fast |
| Placement | Floating |
| Difficulty | Medium |
Where it works and how to spread it
Red root floaters shine in open-top, high-light nano and aquascaped tanks where the colour can be seen from above. They spread by side shoots and thicken into a raft; simply lift out excess to thin. Keep them away from strong filter flow, which breaks up the raft and wets the leaves.
What goes wrong
The main enemy is water on the leaves. Surface agitation, spray from the filter return, or condensation dripping from a tight lid all wet the leaf tops and cause them to melt away. Keep the surface calm and the air above humid but not dripping. If the plants stay stubbornly green, they need more light, not more fertiliser.
More plants in this series
- Amazon frogbit (Limnobium laevigatum) — the easy green floater
- Duckweed (Lemna minor) — the tiny nutrient sponge
- Water lettuce (Pistia stratiotes) — the big-rooted floater
- Alternanthera reineckii — the red stem plant