Anacharis, scientifically known as Egeria densa or Brazilian waterweed, is a popular and fast-growing aquatic stem plant favored by both aquarium and pond keepers. This hardy species is valued for its lush, bright green foliage and its ability to act as an efficient oxygenator. By absorbing excess nutrients from the water column, Anacharis helps to naturally suppress the growth of unwanted algae.
Essential Environmental Requirements
Anacharis thrives best in water temperatures generally preferring a range between 68 and 75°F (20–24°C) in aquariums. While it can tolerate warmer tropical conditions, prolonged exposure above 77°F (25°C) may cause the plant to struggle or “melt.” It prefers a neutral to slightly alkaline pH, ideally between 6.0 and 8.0.
The required lighting level for Anacharis ranges from moderate to high, with stronger light promoting a denser, bushier growth habit. Under lower light conditions, the stems tend to stretch and grow sparser leaves as they reach toward the surface. Anacharis is classified as a water column feeder, meaning it absorbs nutrients directly through its leaves and stems rather than relying heavily on a nutrient-rich substrate.
Step-by-Step Planting Methods
Before planting, prepare the Anacharis cuttings, which are often bundled together when purchased. Carefully remove any binding material, as a tight band can damage the tissue and cause the plant to rot once submerged. Inspect the base of each stem for any crushed or decaying sections, trimming off the damaged ends with sharp scissors to ensure a clean cut.
For stems that will be anchored in the substrate, gently remove the lower leaves from the bottom two inches of the stem to expose the tissue. Use a pair of long tweezers to place the prepared stem end approximately two inches deep into the substrate, taking care not to crush the delicate stem. Space individual stems about an inch apart to allow for lateral branching and future growth, creating a full, dense appearance over time. This rooted method is preferred for creating a background mass in an aquarium or pond.
Alternatively, Anacharis can be allowed to float freely on the water’s surface. Simply drop the prepared stems into the water, and they will quickly begin to absorb nutrients and grow. Floating is effective for providing cover for fish fry and for quickly establishing the plant, as it grants immediate access to the strongest light source. Floating stems may naturally develop fine roots and can then be guided into the substrate to transition to the anchored method.
Successful Establishment and Ongoing Care
After planting or floating, Anacharis may undergo initial stress known as “melting,” where some lower leaves turn soft, brown, and detach. This response is common as the plant adjusts to the new environment’s water chemistry, temperature, and lighting. If melting occurs, promptly remove the decaying material from the water to prevent fouling the water quality. The plant is resilient and will recover quickly, sending out new, healthy growth from the top of the stem.
While Anacharis does not require carbon dioxide (CO2) injection, it thrives when supplemented with liquid fertilizers that target the water column. Dosing a complete liquid fertilizer once or twice a week supports its fast growth, especially under high lighting conditions. When the stems reach the water surface, regular pruning becomes necessary to manage its rapid growth and maintain the desired shape.
To prune, simply snip the top section of the stem; the cut-off portion can be replanted or allowed to float to propagate new plants. Trimming the main stem encourages the plant to branch out laterally from the cut point, which results in a bushier, more dense plant mass. This maintenance controls the plant’s size and promotes lush, vibrant growth.