Elodea canadensis

Scientific name: Elodea canadensis

Family: Hydrocharitaceae

Usual maximum size in aquariums: 25 - 140 cm (9.84 - 55.12 inch)

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Recommended pH range for the species: 6.7 - 7.5

Recommended water hardness (dGH): 4 - 18°N (71.43 - 321.43ppm)

0°C 32°F30°C 86°F

Recommended temperature: 20 - 24 °C (68 - 75.2°F)

Reproduction of the plant: Cuttings

Origin (in the wild): North America

How fast these plants grow: Fast

Recommended substrate: Gravel

Demands on lighting: Bright

Ideal placement in a fish tank: Background

Family

Hydrocharitaceae

Common Name

Canadian Waterweed

Origin

Elodea canadensis is native to North America, where it thrives in slow-moving freshwater bodies such as lakes, ponds, rivers, and canals. Over time, it has spread globally and is now considered invasive in many parts of Europe, Asia, and Australia. Its rapid growth and ability to outcompete native vegetation make it a dominant species in non-native environments.

Growing Conditions

This plant grows fully submerged and does not adapt well to emersed conditions. It thrives in a rocky or gravel substrate but can also be left floating in the aquarium. The plant prefers bright lighting but can tolerate moderate light levels. It grows best in water temperatures ranging from 20 - 24 °C (68 - 75.2°F), with a preferred pH range of 6.7 - 7.6 and water hardness between 4 - 18 dGH.

Under optimal conditions, the plant exhibits fast growth, with stems extending up to 3 meters (~9.84 feet). Regular trimming may be necessary to prevent it from overtaking an aquarium.

Propagation

Elodea canadensis is an extremely easy-to-propagate species. It reproduces vegetatively through stem cuttings and fragmentation. To propagate, take a healthy cutting from the main plant and remove the bottom leaves. Place the cutting into the substrate, ensuring the stem is not crushed, or let it float freely in the tank. Within days, new roots will form, and the plant will continue growing.

In the wild, this plant spreads rapidly as broken fragments detach and establish themselves in new locations. This ability to colonize new areas is why it is classified as an invasive species in many regions.

Difficulty

Easy – Elodea canadensis is one of the most beginner-friendly plants in the aquarium hobby. It requires minimal care, grows rapidly, and does not need additional CO₂ supplementation or fertilizers to thrive.

Planting Area

Due to its fast growth and ability to reach the surface, Elodea canadensis is best suited for the background of an aquarium. It can also be used as a floating plant to create shaded areas, reducing algae growth and providing cover for shy fish and fry.

Short Description

Elodea canadensis, commonly known as Canadian Waterweed, is a hardy, fast-growing aquatic plant widely used in aquariums and outdoor ponds. It is highly adaptable and can grow as a planted or floating species. Its long, trailing stems are covered in small, bright green leaves that provide shelter for fish, shrimp, and small aquatic creatures.

In aquascapes, it serves as an excellent oxygenator, helping to maintain water quality and prevent excessive algae growth. However, due to its rapid spread, regular trimming is essential. Discard unwanted cuttings responsibly—never release them into natural waterways, as they can quickly become invasive.

In ideal conditions, Elodea canadensis may produce small white flowers if the stems reach the water's surface, though this is rare in aquariums.