Anacharis (Egeria densa) Care Guide – How to Grow and Maintain in Aquariums

Anacharis is one of the most widely available and beginner-friendly aquatic plants in the aquarium trade. It is commonly referred to as Brazilian Waterweed or Elodea. Botanically, it has been reclassified and is now correctly identified as Egeria densa.

Renowned for its hardiness and versatility, Anacharis is a top choice for aquarists, especially beginners looking to introduce live plants into their tanks. It thrives in a wide range of conditions, but like all aquatic plants, it requires proper care. Without the right environment, it may deteriorate quickly.

Origin

Anacharis is native to North and South America, where it thrives in a variety of freshwater environments. Due to its rapid growth and adaptability, it is classified as an invasive species in some regions. Its widespread availability makes it one of the most affordable and accessible aquatic plants, further contributing to its popularity among aquarists.

Planting Anacharis

Anacharis features long, trailing stems that can grow up to 3 feet (~91 cm) in length. The leaves vary in color from light green to deep green, growing densely along the stem, creating a lush and natural aesthetic.

If left unanchored, Anacharis will naturally float at various depths, adapting to temperature and light conditions. This floating behavior is more commonly observed in outdoor ponds than in aquariums. The plant is highly valued for its role in oxygenation and water purification, making it one of the best choices for improving overall water quality.

Many aquarists purchase Anacharis in bunches, often held together by a lead weight, and simply place it in the tank to float freely. However, a more effective approach is to remove the weight and plant the stems individually in the substrate. For the best visual effect, plant groups of six stems, spaced 2 inches (~5 cm) apart. Anacharis is also commonly used to conceal aquarium equipment, such as heaters and filter pipes, while providing excellent cover for fish fry when left floating at the surface.

For optimal growth, Anacharis requires moderate to bright lighting, with a recommended intensity of two watts per gallon (~4.54 liters, ~1.20 US gallons) of water. However, excessive lighting can lead to yellowing leaves and plant deterioration, so it's crucial to maintain a balanced light cycle.

This plant is highly effective at absorbing CO₂, nitrates, and phosphates, significantly improving overall water quality. While its natural filtration ability may help reduce the need for frequent water changes, maintaining a consistent water change schedule - especially during its initial growth phase - promotes stronger, healthier plant development.

Anacharis primarily absorbs nutrients through its leaves, but when planted in the substrate, it also develops a root system that draws nutrients from fish waste and organic detritus. Once well-established, it grows rapidly, making regular pruning essential to control its spread and prevent algal overgrowth.

Propagation

How to propagate Anacharis: Simply take cuttings from a healthy plant and replant them in the substrate or let them float freely. To encourage new growth, take cuttings from a healthy mother plant and replant them directly into the substrate or let them float freely. Given the right conditions, these cuttings will quickly develop roots and establish themselves.

For optimal growth, supplementing with liquid fertilizers or root tabs can be beneficial, particularly in aquariums with low CO₂ levels. Since Anacharis absorbs nutrients primarily through its leaves, water column fertilization is also an effective method to support healthy development.

In outdoor ponds, Anacharis is prized for its oxygenating properties, making it a valuable addition to natural filtration systems.

Potential Issues

Although Anacharis is a hardy and fast-growing plant, it is not without challenges. Algae-eating fish, snails, and plecos may feed on its leaves, sometimes consuming large portions of the plant. Some aquarists even use Anacharis as a natural food source for their fish, particularly when leaving their tanks unattended for extended periods.

When kept in ideal conditions, Anacharis may produce delicate white or pale purple flowers that emerge above the waterline. As a dioecious species, each plant develops either male or female flowers, meaning that cross-pollination is required for seed production. In pond environments, insects typically facilitate this process, whereas in aquariums, manual pollination using a small paintbrush can be attempted.

Anacharis is closely related to Elodea nuttallii, with the primary difference being leaf size. While Elodea nuttallii features smaller, narrower leaves, Anacharis is characterized by densely whorled leaves arranged in groups of three per node.

Common Issues and Solutions

Due to its rapid growth and invasive nature, Anacharis should be disposed of responsibly. When pruning, place cuttings in sealed bags before discarding them to prevent accidental introduction into natural water systems. Never release Anacharis into local ponds, lakes, or rivers, as it can outcompete native plant species and disrupt delicate ecosystems.

Providing proper care and maintenance is crucial. Anacharis is resilient, but without adequate light and nutrients, it can melt away within weeks. Regular pruning and stable water parameters will ensure healthy, long-term growth.

Q&A

As part of merging aqua-fish.net/answers with related content, the following question and answer were moved here on March 25, 2011. You are welcome to submit new questions at the bottom of this page, ensuring they are unique and not yet answered.

• Where can I buy Anacharis?

  Answer: Anacharis is widely available at local aquarium stores and online retailers. If a store does not have it in stock, they can often order it upon request.

  To find a seller near you, try searching for buy Anacharis using DuckDuckGo or your preferred search engine. We do not link directly to specific stores, as availability may change over time, and links can become outdated.