Anacharis, commonly known as Brazilian Waterweed (Egeria densa), is a fast-growing aquatic plant widely used in the aquarium hobby. This species is highly valued for its ability to improve water quality and provide shelter in aquatic environments. Anacharis can definitively grow floating in an aquarium; it is a successful and often preferred method for cultivation. It thrives when unanchored, making it a versatile and low-maintenance choice for aquarists.
How Anacharis Absorbs Nutrients While Floating
Anacharis is classified as a true aquatic plant, or hydrophyte, meaning its physiology is adapted to a fully submerged existence. Unlike many terrestrial or semi-aquatic plants, it does not rely on a complex root system anchored in substrate for its primary survival. Instead, it functions as a column feeder, absorbing nearly all necessary minerals and compounds directly from the surrounding water.
The leaves and stems are highly efficient at taking in nutrients like nitrates, phosphates, and essential trace elements. This mechanism allows the plant to thrive even in bare-bottom tanks or when floating freely near the surface. While the plant may develop fine, white adventitious roots, these are primarily for anchoring or stabilizing the stem, not for major nutrient uptake. Its proficiency at absorbing excess nutrients directly from the water column makes it an excellent competitor against nuisance algae.
Essential Care Requirements for Floating Anacharis
To ensure floating Anacharis thrives, providing high light intensity is necessary, as the plant is a rapid grower. Because it is unplanted, the stems naturally float near the surface, giving them close access to the light source. Moderate to high illumination encourages dense, bushy growth and vibrant, dark green coloration.
Since the plant absorbs nutrients almost entirely from the water, liquid water column fertilization is the most direct way to support robust growth. Supplementing with iron and a balanced macro-nutrient solution is beneficial, particularly in tanks with low fish stock. The plant is effective at consuming nitrates, which helps regulate the nitrogen cycle in the aquarium.
Anacharis is tolerant of a wide range of water parameters, but it prefers temperatures between 60°F and 82°F for optimal health. Maintaining a gentle water flow around the floating stems is helpful, as it ensures that fresh, nutrient-rich water moves consistently past the leaves and stems. Stagnant conditions can inhibit nutrient exchange, although the plant remains resilient.
Practical Uses and Maintenance of Free-Floating Stems
Free-floating Anacharis is frequently utilized as a temporary plant in quarantine tanks or breeding setups. Its rapid growth and high oxygen production make it an excellent choice for stabilizing new or temporary environments. The dense, tangled masses of floating stems offer immediate cover and shelter for fish fry and small invertebrates like shrimp.
The proximity to the light source accelerates its growth rate, requiring frequent pruning to prevent shading the water surface. When the stems become too long or dense, they should be trimmed by snipping a section below a leaf node. The removed stem cuttings are highly viable and can be floated elsewhere for easy propagation, quickly becoming new, full plants. Failure to maintain a balance between high light and adequate nutrient levels can lead to excessive algae growth on the leaves, necessitating prompt trimming of the affected stems.