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Anacharis (Egeria densa)is a fast-growing plant that grows easily in medium to large home aquariums as well as outdoor ponds. These lush and tall aquatic plants do well in a range of water parameters, light strengths, and temperatures, making them an ideal choice for beginners who are new to the hobby.
Read this article to learn everything you need to know about, growing, propagating, and caring for the Anacharis plant in your freshwater aquarium.
A Brief Overview Of Anacharis
|Scientific Name||Egeria densa, Elodea densa|
|Common Names||Anacharis, Elodea, Giant Elodea, Brazilian Elodea, Brazilian Water Weed, Large-flowered Waterweed, Pondweed|
|Origin||South America, Brazil, Uraguay, Argentina, Introduced widely|
|Lighting||Moderate-high, 100-250 PAR (Umols)|
|Temperature Range||50 – 77°F|
|Height||To over 6 feet|
|pH Range||7.0 – 8.0|
|Feed Type||Column Feeder|
Origins And Habitat
The Anacharis plant, Egeria densa, is a South American species that naturally grows wild in Brazil, Uraguay, and Argentina1. It has been spread to many countries around the world, including the United States, Mexico, Chile, parts of East Africa, Europe, Japan, Australia, and New Zealand.
Egeria densa grows in slow-moving or still water in lakes, ponds, and rivers. It is a fully aquatic plant that can be found in pretty deep water, especially if it has good clarity.
What Does Anacharis Look Like?
Anacharis is a tall aquatic stem plant that can reach over 6 feet tall in nature. It can grow both from the substrate or as a floating plant.
The Anacharis plant consists of long, upright sturdy green stems, with narrow leaves arranged in whorls. Both the stems and leaves of this aquarium plant have green coloration.
Anacharis plants grown in ideal conditions and parameters will be dark green, while those that aren’t quite as happy tend to be lighter, with bright green leaves.
Each leaf measures about an inch in length and about 1/8th of an inch across. The leaf blades are very finely toothed along their edges. Anacharis stems are pretty fragile and typically about 1/8th of an inch in diameter.
The Anacharis plant typically has two different types of roots. Both kinds of roots have a white coloration.
Anacharis plants have roots that grow from the bottoms of the stem and into the substrate, as well as longer roots that grow into the water from along the stem. The longer roots that grow from the stem are used for absorbing nutrients from the water column.
Placement And Lighting
The Anacharis plant gets pretty tall and is best suited as a background plant in the aquarium. Another effective way to position taller plants is to start them on one end of the aquascape, using shorter and shorter plants towards the middle.
Alternatively, you can simply float this plant in the aquarium. This is a great option if you aren’t too worried about aquascaping and rather wish to provide hiding spaces in a breeding tank.
Whatever your use, bear in mind that Anacharis has a very fast growth rate, and can grow very tall. This makes it a good plant for a larger size tank.
Anacharis grows best in moderate to strong light. Aim for a PAR rate of about 100-150 for the best growth rate.
Plants grown under this light will have a dark green color and a shorter growth form, with more branches from the stem. In low light, these plants tend to grow tall and sparse with light green leaves that are widely spaced along the stem.
What Are Good Tank Mates?
Anacharis has some great benefits for the fish in your aquarium. This plant increases the available oxygen content of the environment when growing well in good tank conditions. It also provides dense shelter for fish at all levels of the aquarium.
Small fry and inverts like shrimps can find great hiding places within the dense stems and leaves of Anacharis to stay safe from predators.
Good Tank Mates
Anacharis is an ideal tank mate for most cool and tropical freshwater fish. Ideally, fish species that enjoy the same water parameters and have the same tank requirements should be selected.
Livestock that prefer harder, slightly alkaline water below about 77°F should be kept with this plant. A couple of great options include:
- Most tetras – like neons or black skirt tetras
- Corydoras catfish
- Cherry Shrimp
Fish Species To Avoid
Plant-eating fish will feed on the Anacharis plant so it is best to avoid fish like goldfish and cichlids. If, however, you don’t mind the plants taking some damage and want to provide your fish with another natural food source, this fast-growing plant is a viable option.
It can be a bit of a balancing act to grow enough of this plant depending on heavily stocked your aquarium is though.
Feeding And Fertilization
Anacharis is primarily a column feeder, although they do also extract some nutrients from the substrate. This makes them great plants for fish tanks because they act as water purifiers by helping to soak up excess nutrients in the aquarium from fish waste.
In a well-stocked aquarium, Anacharis will get most or all of the nutrients it needs in this way, but in a plant-only aquarium, or if growing this plant under strong light and with added CO2, fertilizing with a proper aquarium fertilizer is recommended. If you are looking for a great all-in-one fertilizer, check out APT Complete.
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How Much And How Often To Feed Them
If you are growing Anacharis under strong lighting and with added CO2, a weekly dose (after your regular water change) of a balanced liquid fertilizer will be more than sufficient for this plant. Follow the instructions on the specific product you are dosing for best results.
Many aquarists are able to grow Anacharis without CO2 injection in the home aquarium, so if you have a low-tech setup, this is still a plant you can grow.
Anacharis will definitely appreciate injected CO2 though and will have a faster growth rate, with darker green leaves and denser stem growth under such conditions. When considering whether to start using CO2 in your planted aquarium, remember this rule:
Aquatic plants have 3 important requirements for healthy growth. These are:
- Carbon Dioxide
It is important to provide all three in balance. This means that if you provide a lot of light for example, without providing nutrients and CO2, your plants will not be able to use that light for growth, and the imbalance will probably result in excessive algae growth or some other issues. If you are looking for a quality CO2 system, CO2 Art is the best in the business.
A budget friendly version of the SE series. This has the quality of CO2 art with a great price. Highly recommended!
How Much CO2 Do You Need?
Any increase in available CO2 will benefit your Anacharis plant in a well-balanced system. CO2 in high concentrations can be deadly to the fish and other livestock in your aquarium, however, so keep your levels below 30 ppm.
Since plants can only use carbon dioxide during the day, set your CO2 system on a timer that shuts off at the same time as your lights.
Having your CO2 injection system start up about 2 hours before the lights come on will give the CO2 time to build up to optimal levels before the lights switch on again.
Care and Instructions
Anacharis is an easy aquarium plant to care for. Trimming and pruning the Anacharis plant might keep you pretty busy if you are growing it in a small tank, however. If you want a quick video, here is a good one from The PlantGuy. I’ll go into more detail below:
Let’s take a closer look at some of the keys to Anacharis care:
Planted Aquarium Parameters
The Anacharis plant is best suited for medium to large aquariums because it will quickly outgrow nano tanks. A 15-gallon tank is probably about the minimum size if you want to plant Anacharis.
These plants grow best in cooler water tanks with fairly hard water, although they can be grown in tropical aquariums. A temperature of between 50 and 77°F is recommended for growing this plant in the home aquarium, although they are able to overwinter in lower temperatures in outdoor ponds.
Maintaining good water quality and healthy water conditions is the most important key to success in keeping all aquarium plants and animals.
A good filter is vital for healthy water conditions but you will also need to roll up your sleeves and perform partial water changes on a regular basis.
Provided your aquarium is not overstocked, a weekly water change of about 25% is usually a good routine to have. The frequency and volume of your changes are going to vary though, depending on your tank size, filter capacity, and livestock.
Providing good filtration is key to maintaining safe and healthy aquarium water and providing good care to your plants and animals. Good Anacharis care doesn’t rely on any specific type of filter though.
One important consideration with a fast-growing and somewhat fragile species like Anacharis is that it can clog filters. A good way to prevent this is to use a filter with a pre-filter sponge over its intake that keeps larger particles from being sucked in.
If you do find your filter media becoming clogged with stems and leaves, be sure to use your tank water to rinse out the sponges. Using regular tap water can kill off the beneficial bacteria in the sponge, resulting in a dangerous water condition.
The Anacharis plant is more adapted to stillwater and gently flowing river systems without strong currents. It is best to grow these plants in aquariums with lower flow rates or position the plant in an area of the tank without strong flow. Some of the best ways to protect these plants are:
- Grow them in a position far from your filters outflow
- Direct your filters outflow upwards towards the water surface
- Use a piece of driftwood or another hardscape feature in front of the outflow of the filter to break up the current and shelter the plant
- Use a filter that is an appropriate strength for the volume of your aquarium
Apart from performing regular water changes in your aquarium, take care to keep the surface of the substrate clean by removing uneaten food, fish waste, and other substances with your gravel vacuum.
You will also need to clean the glass of your aquarium from time to time as algae develop. Use your algae scraper for this task just before a water change and the loosened algae can then be siphoned out of the tank.
Testing Water Conditions
Testing your water conditions is the best way to know about what’s going on in your aquarium to a finer level. Even though the water in your tank may look crystal clear, the levels of ammonia and nitrites should be monitored regularly, especially if you keep fish.
Use your liquid test kit to monitor:
Another important water parameter to keep an eye on is water temperature. Use a thermometer to confirm that your heater is maintaining your aquarium at the right temperature.
How To Set Up Your Aquarium Tank
Anacharis is a pretty easy-going plant that doesn’t require a whole lot of extra care and preparation before being added to the tank. To highlight this point, this plant can be grown in a bare tank by simply floating it in the aquarium.
If you prefer to grow this plant rooted, you will first need to lay down a layer of a substrate of your choice. If Anacharis is the only plant you’re going to grow in the tank, aquarium soil will not be needed and you can use sand or gravel instead.
Whichever type of substrate you choose to use, a layer of about 2 inches deep will be ideal for the growth of healthy roots.
How To Propagate
Anacharis is one of the easiest aquarium plants for beginners to propagate in the home aquarium. Simply take stem cuttings from a healthy, mature specimen and plant them in the substrate.
4 inch long cuttings are a good size for propagating new plants. Always take care to plant Anacharis cuttings right side up though.
A method that can be very effective is to float the cuttings in the aquarium until they have developed a root system. Then anchor them at the bottom with a weight, and without pushing them into the substrate.
Although this method does take a little more patience, it causes the Anacharis plant to develop roots and send them into the substrate by itself. The benefit of this is that the plants don’t melt in the substrate while rooting.
Health And Disease
Anacharis plants are not usually prone to health issues, but there are a few things to look out for. Let’s take a closer look at health issues in Anacharis:
Signs Of Health
A healthy looking plant has a dark green coloration with plenty of leaves whorled around each stem.
Signs Of Ill Health
Anacharis that has been grown in unfavorable conditions will usually be tall and thin, with weak stems and few leaves growing widely spaced along the stems.
Common Health Issues And Treatment
Melt is a common problem with many new aquarium plants. In the case of Anacharis, melting plants become very soft and are easily sucked up by your filter.
It is best to remove melting Anacharis stems before it gets to this stage. Fortunately, these plants typically bounce back quickly.
Although the Anacharis plant is great for suppressing blue-green algae in the tank water, hair algae on the stems and leaves can become a problem in aquariums that have lighting and nutrient levels that are out of balance.
The best way to stop the growth of hair algae is to reduce the lighting period. Lowering the strength of the lighting, and using CO2 can also be helpful.
Pests like snails (such as apple snails) and worms can often find their way into your aquarium by hiding in the roots, stems, and leaves of new plants. To reduce the risk of introducing these pests, rinse your plants off carefully before adding them to your tank.
A 1 minute or less dip in a very mild bleach solution of 1 part bleach to 20 parts water can also help by killing off these organisms. If you do dip the plants in bleach, just be sure to rinse them off carefully with dechlorinated water before adding them to your tank.
Where To Buy
Anacharis plants are common and a popular aquarium plant. They are usually very affordable. This plant is usually sold in bundles tied together with rubber bands.
You can usually find Anacharis for sale at your local fish stores or pet store, or check out an online retailer. Online can have an advantage as in general Anacharis specimen selection can be risky at local stores. This is because they are so popular and often giving similar treatment that feeder goldfish get. You will usually get a better specimen online and have less of a risk for pests online.
Excellent as a food source and sucks up nutrients in an aquarium. One of the easiest freshwater plants to care for
Do they need CO2?
Anacharis can be grown in low-tech aquariums without CO2. If you do have a CO2 injection system, don’t worry, you can still grow Egeria densa.
Is this the same as hornwort?
Although the two plants look pretty similar to one another, Anacharis (Egeria densa) is a different species to Hornwort (Ceratophyllum demersum). The two plants do have very similar care requirements though.
Do goldfish eat them?
Goldfish love Anacharis and will happily munch on this plant. This is great for the fish but not so great for your carefully planned aquascape, so think carefully before stocking the two together.
How fast do they grow?
Anacharis grows fast. In the right conditions, these plants grow like a weed, quite easily growing over a foot a month. Of course, plants grown in poor conditions or outside of their preferred parameters might not grow at all.
Is Anacharis good for ponds?
Anacharis is a great plant for ponds. Ponds are a much less controlled environment than aquariums, however, so be careful to avoid letting this plant get into waterways outside of its natural range where they can become invasive.
Anacharis is a great plant for beginners looking for a tall, fast-growing species that will produce plenty of beautiful green stems in their aquarium. Just remember that these plants do need at least moderate lighting and do not enjoy a very high water temperature to grow at their best.
Have you had experience with Anacharis? If so, leave a comment below, share, and join the conversation. Thanks for reading and see you next time!
Mark is the founder of Aquarium Store Depot. He started in the aquarium hobby at the age of 11 and along the way worked at local fish stores. He has kept freshwater tanks, ponds, and reef tanks for over 25 years. His site was created to share his knowledge and unique teaching style on a larger scale. He has worked on making aquarium and pond keeping approachable. Mark has been featured in two books about aquarium keeping – both best sellers on Amazon. Each year, he continues to help his readers and clients with knowledge, professional builds, and troubleshooting.