Anacharis (Egeria densa) is a popular aquarium plant prized for its attractive growth, versatility, and adaptability to varying water conditions. The plant is readily available for purchase in fish stores and from what I know, it is very cheap because a bunch can be obtained for a few bucks.
The plant is suitable for both expert and beginner hobbyists who are looking to try out a new stem plant with minimal care requirements.
Anacharis offers a lot of benefits to the aquarium, it is an excellent oxygenator, provides foraging ground, shelter, and hiding spots for the offspring of diverse aquatic animal species. Anacharis is good for aesthetics, it has tall stems and a bright green coloration which offers a beautiful contrast in aquariums.
In this article, I will talk about this hardy plant — its habitat, appearance, common problems, and how you can plant and care for Anacharis in an aquarium. Let’s get started.
|Important: Egeria densa enjoys longstanding popularity in the aquarium hobby but behaves invasively in many states. This invasive species produces unwanted effects such as:
– clogging waterways and hydroelectric turbines,
So, make sure it is not banned in your state and you do not buy or sell it illegally.
Quick Notes about Anacharis
|Other Names||Brazilian waterweed, Anacharis densa, Elodea densa, Leafy Elodea, Elodea, and Egeria|
|Tank Size (minimum)||10 gallons (40 liters)|
|Optimal Lighting||Moderate to high|
|Optimal pH||6.0 – 8.0|
|Optimal GH||2 – 20|
|Optimal Temperature||20 – 24 °C (68 – 75°F)|
|Substrate||any / floater|
|Growth Rate||Very fast|
|Placement in Tank
|Size (untrimmed)||up to 1 m and more (3 ft. and more)|
Origin and Taxonomy of Anacharis
Anacharis is the common name for the Brazilian waterweed “Egeria densa”, which was formerly known as Anacharis densa & Elodea densa, with Egeria densa being the present scientific name.
Anacharis is a species of the genus Egeria and this genus comprises three species of aquatic plants in the flowering plant family Hydrocharitaceae.
Egeria was formerly included in the related genus Elodea (the Waterweeds), however, it differs from Elodea due to a distinction in physical features.
Egeria plants have leaves in whorls or four-six, unlike Elodea that possesses three. Also, Egeria has a larger prominent flower with broader white petals.
The classification of this species as Egeria densa was established by Jules Émile Planchon, a French botanist in 1848. The earliest report of this plant outside of its native range is from 1893 when a plant was collected on Long Island, New York.
Anacharis is known by many common names as well as binomial names, these include the following: Leafy Elodea, Brazilian waterweed, Brazilian Elodea, Anacharis densa, Elodea densa, and Egeria.
Habitat of Anacharis
Anacharis (Egeria densa) is native to South America, in countries like Argentina, Brazil, and Uruguay.
The plant has become naturalized in most parts of the United States and also present in other parts of the world: Africa, Asia, and Europe due to its distribution as an aquarium plant. Currently, this species is naturalized in at least 27 countries around the world in subtropical and temperate regions.
The plant inhabits still and slow-moving waters: lakes, ponds, ditches, streams, rivers, and canals, where it forms dense mats and outcompetes native and non-native species.
Description of Anacharis
The variable pigmentation exhibited by the plant is probably due to the water condition in the environment it lives in.
The plant’s height is dependent on the depth of water surrounding it. In the wild, it can attain a massive height of up to 3m (9 ft), but this is much lesser in captive care.
Interesting fact: A 7 m (21 ft.) rooting depth has been observed in a high altitude lake in Colombia.
Anacharis has finely serrated, narrowly lanceolate, sessile leaves which are arranged in whorls of 4-6, 1-3 cm (0.4 – 1 inch) long and 2-5 mm wide with a pointed leaf tip.
The plant will grow to the water surface, then create branches that spread out horizontally to form a mat or thick canopy. As mentioned earlier, the leaves of this plant grow in whorls, and they often occur in sets of four at a node.
Also, the plant is dioecious; this simply implies that male and female flowers exist on separate plants.
The flowers approximately 20 mm (0.8 inches) with 3 broad petals, white, and possess 9 yellow anthers. These flowers bloom above the surface of the water and it is rarely seen in the aquarium.
The long green delicate stems of Anacharis are sparsely branched with short internodes, also present are filament-like or stringy white roots that form at the base of plants and some nodes.
Note: The plant is often confused with species of Elodea and Hydrilla. Based on observations, Egeria has whorls of 4-6, Elodea with whorls of 3 whereas Hydrilla has whorls of 5. Besides, Egeria densa has larger leaves and prominent flowers, and a smooth midrib on the underside of the leaf.
Tank Requirements and Water Parameters
This plant cannot be kept in nano tanks. Anacharis is great for ponds.
A minimum tank size of 10 gallons (40L) is required for keeping Anacharis. The bigger the better.
Water type, Temperature, Hardness, and pH:
Temperature: According to the study, the optimum temperature for Egeria densa is 21°C (70 F) in culture.
This hardy plant can easily tolerate temperature as low as 59 °F (15 °C) and as high as 82 °F (28 °C). Even more, Anacharis appears to have some degree of tolerance for cold waters. It can survive winter in a ditch under a cap of ice. However, freezing is lethal.
pH: The plant prefers water pH in the range of 6.0 – 8.0.
Hardness: In general, Anacharis does not care about hardness. It will do well in tank water with hardness values 2-20 GH. It can tolerate hard water as well.
However, it can be a little bit tricky to transfer this plant from very soft to hard water. It can melt. Surprisingly, we don’t have this problem when we transfer it from hard to soft water.
The plant needs moderate – high lighting to photosynthesize and grow optimally. Under intense light, the plant will release a great deal of oxygen in the tank. Ideally, the lights should be kept on for at least 8 hours daily.
The results of the study show that Anacharis is able to increase its photosynthetic rate with increasing light in a nearly linear fashion. At low levels of light, the growth patterns favor the elongation of shoots (instead of increased shoot number) and the development of upper (canopy) branches.
Anacharis can grow either way as planted or as a floating plant. This is primarily because these plants are able to extract nutrients from both the sediment and the water column.
However, once planted it start growing way faster.
Anacharis can grow in almost any kind of substrate since it feeds through the water column and substrate. However, my top choice is aquarium gravel or sand preferably with aqua soil underneath to provide nutrients.
CO2 and Fertilizers:
The plant will thrive in tanks without CO2. It also does not rely heavily on supplements (fertilizers) to grow.
However, if you desire optimal growth and lush appearance for this plant, then it’s best to add fertilizers from time to time (on a weekly or bi-weekly basis).
Important: If you keep shrimp in the tank with the Anacharis, I would highly recommend reading my articles:
CO2 in a Planted Tank Guide
CO2 in a Shrimp Tank
How Copper Affects Dwarf Shrimp
Shrimp Safe Plant Fertilizers
The point is that a high level of CO2 and Copper (most fertilizers contain copper) is extremely dangerous to the shrimp.
Care and Maintenance of Anacharis
Anacharis is easy to care for, and you wouldn’t run into many problems with this plant. Interestingly, much of the required care has to do with pruning the shoots to halt them from overrunning the tank since they can grow to the surface of the water.
For a dense and forest-like view; trim them regularly. When you trim the plant, it will shoot the buds that go to the sides. That is how you can make this plant bushy.
Allow them to grow densely and clip them just a little bit, especially if you had them placed in the background.
Under optimal conditions, Anacharis grows very fast. In one month it can easily double or triple in size!
Regular additions of fertilizer will help the plant grow even more vigorously and develop new shoots, although it can thrive without it. Additionally, be sure to carry out partial water changes by replacing the tank water weekly or every other week to keep the water clean and healthy for aquatic life.
Test the water parameters weekly to maintain ideal water values, and don’t forget to clean the filter media to ensure its efficiency.
Interesting fact: According to the study,
- Egeria densa is able to tolerate, in laboratory conditions, a salinity of up to 8 g/l, and in its habitat in the basin of the Valdivia River, 5 g/l.
- A salinity of around l g/l promotes growth and biomass production of the
- In salinities of 2 g/l and higher, the development of Egeria densa gradually deteriorates, which leads to a decrease in growth, less production of roots, and a sharp drop in photosynthetic
Planting and Propagation of Anacharis
Planting and propagation of Anacharis is something anyone can pull off. Anyway, follow this guide to cultivate Anacharis in your tank.
First, you need to gently remove the band that holds the stems together.
Afterward, closely examine the stems for likely damages, do well to eliminate damaged or dead leaves with a curved blade. You can equally cut off the banded area if it is damaged.
Next, split the stems into separate portions and disinfect them properly to get rid of hitchhikers (if any) that may be clinging to the leaves, these could be tiny snails and micro worms. Do this to avoid possible pest or disease infestation.
Furthermore, make sure to trim the leaves at the base of the stems because they will decay if anchored in the soil like that.
The proper way of planting the individual stems is to bury it about 1-2 inches (2.5 – 5 cm) deep in the substrate to prevent it from floating to the surface shortly after planting.
You can use a pair of tweezers (link to check the price on Amazon) to gently place the stems into the substrate to avoid damage.
Important: Avoid planting the stems too close to one another, such practice is bad because it promotes unhealthy competition for nutrients. Therefore, try to leave just enough distance between the individual plantlets.
Alternatively, you can place the split stems on the surface of the water and allow it to float freely. You just need a few stems to avoid overcrowding at the top which will ultimately block light penetration in the tank.
Some aquarists complain that when they plant Anacharis into the substrate, it started rotting. It is really hard to say why it may happen … So if you have the same problem, you can leave the plant floating in the tank until it plants itself.
Tip: Use some kind of weigh or just wedge it between rocks, driftwood, or some decor. That way no part of them will rot and they will send their roots down into the substrate naturally.
Propagation is incredibly easy too, simply break off some portions from mature plants.
Ensure you take your cuttings from long healthy stems. When you see long aerial roots coming out, cut it right under the roots, and plant it into the substrate. Ideally, it should be at least 4 inches (10 cm) long.
You can also split these stems into smaller pieces before planting.
After some time, the new cuttings will develop roots and continues growing in the aquarium. Notably, under intense lighting and nutrient availability, the new plants will grow rapidly and form branches at the nodes.
Problems Associated with Anacharis
Melt: Unfortunately, the plants may wither days after planting in your aquarium. This occurs as a result of a change in the environment or because there was something wrong with the planting.
Introducing Anacharis into a new tank with different water chemistry will make them stressed and they will respond by shedding old leaves.
Do not worry. Give it some time to acclimate. However, keep in mind that even after the plants have acclimated to the tank, harsh swings in water chemistry can still cause them to shed leaves and decay at the bottom.
Tip: Let them float for some time. They will still survive, but more importantly, roots will come off of them and once this happens you can root the roots into the substrate. So, you will not have to weight it down.
Dormant state: Sometimes the plant just sits in the tank. It does not grow or die. Nothing happens.
Check your light. I would start with a photoperiod of 10 hours on a daily basis to see the reaction. After that, if it does not help, I would start increasing the light intensity slowly.
If it is not planted – plant it.
Add some nutrients.
Trim it. If Anacharis takes over all available space in the tank, it almost stops growing, even if light, feeding, and temperature in the aquarium remain the same.
Overgrowth: Anacharis is a fast-growing plant and it may overrun the tank if left unattended. In addition, they will create shades thereby blocking light from getting to plants at the bottom of the tank. Hence, the plant should be trimmed and discarded from time to time to prevent overcrowding and shadowing at the surface.
Discoloration: As mentioned earlier, Anacharis requires bright illumination to photosynthesize and maintain vibrant coloration. In low light conditions, the plant may exhibit pale green or slight yellowish appearance.
Also, try to maintain good water quality by carrying out partial water changes weekly and keeping the water parameters at the ideal values.
Benefits of Anacharis
Aquascape: The shape and form of Anacharis will offer a beautiful contrast in aquariums. It can be an excellent decorative addition for jungle aquascape.
Removal of excess nutrients: Egeria densa has heavy metal absorption properties. It is helpful in absorbing harmful chemicals that are emitted from fish waste, decayed plant matter, and tap water such as nitrates, CO2, ammonia, and phosphates.
Interesting fact: Biologists also discovered that Egeria densa shows a clear preference for ammonium over nitrates. They also suggested that phosphorus may be more of a limiting factor for this plant than nitrogen, given that P, not N, was tied to increased growth.
Of course, it does not mean that this plant does not remove nitrates from out tanks. Actually, it does it very well. It is just for that, they need to convert nitrates back into ammonium. Unfortunately, it takes them a lot of energy to do so. In addition, they have to compete with beneficial bacteria for the ammonium.
Algae control: Anacharis is extremely effective against algae. It outcompetes algae for the nutrients and suppresses its growth.
Anacharis has allelopathic qualities as it excretes substances that inhibit the growth of blue-green algae and phytoplankton.
Hiding place for fish, fry, and shrimp: Serves as cover and shade for inverts and small fish. It serves as a perfect hiding place for shrimp and fish.
Foraging place: Acts as a buffet of biofilm, which is an ideal first food for newly hatched fry and shrimplets.
Oxygenation: Anacharis oxygenates and aerates the tank water.
Anacharis and Tankmates
Anacharis can be paired with a lot of aquatic species, though the plant is more suited for community tanks housing small peaceful fish that won’t rip their delicate shoots apart.
Here are some examples of compatible species that can co-exist peacefully with Anacharis.
- Corydoras catfish, Neon Tetras, Zebra Danio, Ember Tetras, Guppies, Endlers, Mollies, Otocinclus Catfish, Pygmy Cory Catfish,
- Cherry shrimp, Snowball shrimp, Caridina cf. Babaulti, Ghost shrimp, Amano shrimp, Blue tiger shrimp, Blue Velvet Shrimp, Vampire shrimp, Bamboo shrimp, Cardinal Shrimp, Red Nose shrimp, etc.
- For example, Japanese trapdoor snails, Ramshorn snails, Nerite snails, Malaysian Trumpet snails, Black Devil Snails, Asolene spixi, Rabbit Snails, etc.).
However avoid species that may find Anacharis palatable, e.g. like Koi fish, Goldfish, Oscars, Rainbow, Jack Dempsey, Clown loaches, African Cichlids.
These species can really cause problems in the planted tanks.
Anacharis and most types of crayfish or freshwater crabs are not a good combination as well. These animals will cut, eat, and uproot everything in the tank. So, unless you let it float, it is a no go!
Anacharis is readily available in most local fish stores, and it’s pretty affordable. A bunch of about 5 stems retails at $3-$10.
When shopping for this plant, be on the lookout for sturdy green stems. Getting healthy specimens is vital if you don’t want to have any issues with this plant, the leaves on the specimens should be of light-bright green coloration and it should be free from damages and decay.
Also, the specimens should be about 6-8 inches (15 – 20 cm) in size with healthy-looking stems and leaves. Lastly, if by chance you spot algae patches or black tints on the foliage of specimens, do not purchase.
Note: Although some vendors have ceased to sell Anacharis as an aquarium plant due to its invasiveness, it can still be purchased over the Internet.
Do not forget to quarantine Anacharis before putting it into your aquarium!
- The plant can have parasites, pests like snails, or even predators (dragonfly, damsefly nymphs, etc.).
- It could also be treated with chemicals (pesticide) to remove parasites, snails, etc. However, these chemicals are extremely poisonous to fish, shrimp, and other invertebrates.
To find out more, read my articles:
Anacharis is one of the best plants suitable for freshwater display tanks. The fact that it is vivid, versatile, resilient, and grows rapidly justifies why it is highly sought-after by hobbyists.
I would definitely recommend trying Anacharis for your home aquarium so you can gain first-hand experience of its awesome nature.