Salvinia
Salvinia minima
Also known ascommon salvinia · water spangles
Water parameters
Light and nutrients
Substrate type: epiphyte. Propagation: fragmentation.
Substrate compatibility
| Substrate | pH effect | Nutrient load |
|---|---|---|
| Wood and rock mounts (Hardscape mount) | varies | none |
| Inert sand (Pool filter sand) | neutral / inert | none |
| Inert gravel (Aquarium gravel) | neutral / inert | none |
| Bare bottom (no substrate) (Bare bottom) | n/a | none |
| Aquasoil (ADA Amazonia) | lowers pH | very high |
| Mineralized clay substrate (Seachem Fluorite) | neutral / inert | moderate |
With fish
Origin and habitat
Native to tropical and subtropical regions of the Americas. The genus Salvinia includes several species used in aquariums; the most common is S. minima (water spangles). Salvinia is a floating fern with small, oval, bright green leaves (5–15 mm) arranged in pairs along a branching stem, with a modified third leaf that hangs below the surface as a root-like structure. The upper leaf surface has fine, water-repellent hairs that trap air bubbles, giving the leaves a velvety appearance. Salvinia spreads by fragmentation and budding, forming floating mats on still water surfaces. Several species are invasive in tropical and subtropical waterways worldwide; S. molesta (giant salvinia) is one of the world's worst aquatic weeds. In aquariums, S. minima is the most commonly kept species because of its manageable size (leaves 5–15 mm). Larger species like S. auriculata and the infamous S. molesta produce leaves several centimeters across and are too large for most tanks. S. molesta is one of the world's worst invasive aquatic plants, capable of covering entire lakes and river systems. Do not release any Salvinia species into natural waterways.
Outdoor pond use
- USDA zones
- 8–13 (winter low around -12°C or warmer)
Care notes
Easy floating plant. Grows under low to high light in any water chemistry (pH 5.5-8.5, GH 2-20+), temperature 15–30°C. Growth rate is fast; a small amount doubles in coverage every 1-2 weeks under good conditions. Thin regularly to prevent complete surface coverage. The tiny leaves and trailing structures provide shelter and grazing surface for fry and shrimp. Salvinia absorbs nutrients from the water column through its hanging root-like leaf, helping reduce nitrate and phosphate. Like all floaters, it needs calm water surface; strong current from filter outlets pushes it around and can damage the delicate leaves. Leave a gap in the tank lid to prevent condensation from dripping onto the leaves (which causes rot). Propagation is automatic through fragmentation and daughter plants. In aquaponics, salvinia is less useful than duckweed for nutrient export because it grows slower, but it's more visually attractive. Compatible with all fish. Available from pet stores, aquatic plant retailers, and hobbyist trades at low cost.