Azolla caroliniana
Scientific name: Azolla caroliniana
Family: Azollaceae
Usual maximum size in aquariums: 0 - 2 cm (0 - 0.79 inch)
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Recommended pH range for the species: 6.3 - 8
Recommended water hardness (dGH): 0 - 18°N (0 - 321.43ppm)
0°C 32°F30°C 86°F
Recommended temperature: 15 - 27 °C (59 - 80.6°F)
Reproduction of the plant: Lateral shoots
Origin (in the wild): North America
How fast these plants grow: Normal
Recommended substrate: Without substrate
Demands on lighting: Bright
Ideal placement in a fish tank: Floating
Common Names
Carolina Mosquito Fern, Water Velvet
Origin
Azolla caroliniana originates from North America, where it is commonly found in freshwater habitats like ponds, lakes, and slow-moving rivers. It is widespread across the southeastern United States and extends into parts of Central America.
Quick Overview
- Ideal For: Aquariums, ponds, wetlands
- Difficulty Level: Easy
- Lighting: Bright to medium
Growing Conditions
Azolla caroliniana is a floating plant that thrives on the water’s surface, where it can absorb nutrients directly from the water. It is ideal for aquariums and ponds with still or slow-moving water. The plant forms dense mats, which provide shade and shelter for fish while helping reduce nutrient levels in the water. Bright lighting will promote faster growth, although it can tolerate medium lighting if nutrients are sufficient. It prefers temperatures between 15 - 27°C (59 - 80.6°F) and can survive in a wide range of water hardness (0 - 18 dGH). This species does not require any substrate, making it easy to maintain as a floating plant.
Planting Area
Azolla caroliniana should never be planted in the substrate, as it is a true floating species. It will float freely on the water's surface, where it grows and spreads naturally, providing surface coverage in aquariums, ponds, and paludariums.
Propagation
Propagation of Azolla caroliniana occurs through vegetative fragmentation. As the plant grows, it naturally breaks apart into smaller pieces, or lateral shoots, which continue to grow and spread independently. New plants form quickly, and in the right conditions, the plant can cover the surface of an aquarium or pond rapidly. While Azolla can reproduce sexually through spores, vegetative fragmentation is the primary method of propagation in aquariums.
Difficulty
Azolla caroliniana is considered easy to grow, making it suitable for both beginner and experienced aquarists. It requires minimal care and adapts to a range of water conditions, as long as there is adequate lighting and nutrient availability. Regular thinning of the plant may be necessary to prevent overgrowth, which could block light from reaching submerged plants.
Short Description
Azolla caroliniana is a small floating fern known for its ability to form dense mats on the water's surface. It is valued in aquariums and ponds for its nitrogen-fixing properties, which help reduce nitrate levels in the water. Due to its fast growth and ease of propagation, it is also used as fish food and fertilizer. This plant is ideal for aquascapes that require surface coverage, providing shelter for fish and controlling algae growth by limiting light penetration. Care should be taken to prevent excessive spread, as it can cover the entire surface if not managed properly.