Overview & Origin
Salvinia minima is a floating aquatic fern native to Central and South America. It belongs to the family Salviniaceae and is one of the most popular floating plants in the aquarium hobby due to its attractive appearance and manageable growth rate — faster than Frogbit but much easier to control than Duckweed.
Each "plant" consists of a chain of node pairs, with each node producing two small floating leaves (0.5–1 inch) and a submerged, root-like modified leaf that hangs below the surface and absorbs nutrients. The upper leaf surface has tiny, water-repelling hairs (trichomes) that create a distinctive velvety texture and cause water to bead on the surface.
Basic Care
- Lighting: Moderate to high. Under good light, Salvinia produces compact, rounded leaves. Under low light, growth is slower and leaves are smaller.
- Surface flow: Minimal. Like all floaters, Salvinia doesn't appreciate being pushed around. Baffle filter output or direct it downward.
- Nutrients: Absorbs nutrients through its dangling modified leaves. In stocked tanks, fish waste usually provides sufficient nutrition. Liquid fertilizer boosts growth and color.
- Temperature: Adaptable — grows well from 65–82°F.
Water Parameters
- Temperature: 65–82°F (18–28°C)
- pH: 6.0–8.0
- KH: 2–12 dKH
- GH: 2–12 dGH
Benefits
- Nutrient absorption: Efficient at removing nitrates and phosphates from the water column, helping control algae.
- Shade: Provides dappled shade that many fish species appreciate, especially bettas and gouramis.
- Fry protection: The dangling modified leaves and surface coverage provide shelter for newborn fish.
- Manageable size: Larger than Duckweed but smaller than Water Lettuce — the sweet spot for many aquarists.
Salvinia vs Other Floaters
- vs Duckweed: Much easier to control and remove. Larger, more attractive leaves. Doesn't hitchhike as aggressively.
- vs Frogbit: Smaller leaves, faster spreading. Doesn't develop the dramatic long roots that Frogbit does.
- vs Red Root Floater: Salvinia lacks the red coloration but is hardier, more tolerant of water conditions, and easier to grow.
- vs Water Lettuce: More compact and better suited for smaller tanks. Less dramatic appearance but more manageable.
Maintenance
Salvinia reproduces by breaking into fragments, each of which grows independently. Under good conditions, it can double in coverage every 1–2 weeks.
- Scoop out excess with a net weekly. Keep surface coverage under 50%.
- Easy to remove compared to Duckweed — the larger fronds are easily scooped without leaving tiny fragments behind.
- Removed Salvinia can be composted or given to other aquarists.
Common Problems & Solutions
- Yellowing: Nutrient deficiency. Dose liquid fertilizer, especially iron and nitrogen.
- Leaf damage from condensation: Water droplets on the upper leaf surface cause browning. Ensure adequate airflow between water surface and lid.
- Slow growth: May need more light or nutrients. Also check that water temperature isn't too cold.
Frequently Asked Questions
Is Salvinia Minima invasive?
It can be invasive in warm climates. Check local regulations. In the aquarium, it's much easier to control than Duckweed.
Does Salvinia need CO2?
No — it accesses atmospheric CO2 as a floating plant.
Can Salvinia grow in cold water?
It tolerates down to about 65°F. Growth slows below 70°F but the plant survives.