Salvinia minima - Aquatic Floating Plant Cup

Salvinia minima, or water spangles, is a fast-growing, floating aquatic fern used in aquariums and ponds for its ability to absorb nitrates, provide shade, and reduce algae, but it is considered invasive in many areas and must be prevented from entering natural waterways. It forms a dense carpet on the water's surface, with small, oval leaves that have fine hairs to repel water, and it thrives in still water with bright light. Due to its rapid growth, it requires regular pruning to control its spread. 

Characteristics

Appearance: Small, oval, bright green leaves (0.4–2 cm) that grow in sets of three, with two floating and one hanging below. Fine, water-repellent hairs cover the leaves. 

Growth: Forms a dense mat on the water surface, growing quickly in calm, slow-moving water. 

Habitat: Native to Central and South America; thrives in lakes, ponds, and ditches. 

Aquarium use

Benefits: Absorbs ammonia and nitrates, provides shelter for fish, and blocks excess light to prevent algae growth. 

Care: Prefers bright light and still water (low flow). Can be pruned with tweezers or shears. 

Caution: Grows very fast and can quickly take over a tank; regular removal is necessary. 

Invasive potential

Status: Prohibited in some states, like Florida, due to its invasive nature. 

Risk: Can outcompete native plants and disrupt ecosystems if released into natural water bodies. 

Recommendation: Do not release into outdoor ponds or natural waterways; check local regulations before purchasing.