Hornwort 101: Complete Care Guide (Species, Planting and Propagation)

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Introducing plants to your aquarium has many benefits other than just aesthetics. Plants help keep your tank and fish healthy, provide shelter, as well as oxygenating the water.

If you are looking for an easy plant to grow in your tank, hornwort is perfect for you. Having originated in North America, hornwort’s popularity has caused it to spread all over the world. You can find it growing in the wild throughout each continent, with the exception of Antarctica.

This plant is perfect for beginners. It has a high tolerance for several different water conditions. It grows quickly, and it is easy to propagate. You can either root it in the substrate or use it as a floating plant, which gives you more flexibility when planning the look and design of your tank. 

Most freshwater fish love the hornwort plant. Between that, how easy it is to take care of, and the benefits it comes with, you are guaranteed that buying the hornwort plant is a win-win situation.

The following hornwort care guide will walk you through all the ins and out of buying and taking care of your hornwort.

Hornwort care guide

Hornwort Overview

Hornwort (Ceratophyllum) is one of the trendiest freshwater aquarium plants on the market today. Although the exact number of species remains uncertain due to misidentification, there are approximately 150 species that have been named.

Ceratophyllum demersum is the most popular species among aquarium hobbyists today. It’s the ideal aquarium plant for beginners due to its hardiness and no-fuss nature.

In its natural habitat in the wild, this hardiness can cause serious problems. Because it can tolerate many different conditions, along with its fast rate of growth, this plant has been labeled as an invasive species, spreading easily and quickly to new areas.

Places like New Zealand are suffering from hornwort invasion. These plants have been outcompeting their native plants and causing a disruption with their hydroelectric power generations.

Hornwort is also an allelopathic plant, meaning it produces chemicals that will prevent other species of plants from growing, ensuring it gets more nutrients and space for itself.

Hornwort’s hardiness can be seen all around the world. Because of the popularity of this plant and its high-demand status, it is now stocked in most stores. The hornwort’s rapid growth rate allows it to be grown in vast quantities cheaply, and therefore it can be sold cheaply, as well.

Although the price will vary due to such variables as cost per plant, the retailer’s price, and how many you buy at one time, you can generally expect to pay between $5 – $10 a bunch.

Benefits of Hornwort

Aquarists love hornwort for its vibrant green coloring, regardless of whether it’s floating around the top of the tank, or rooted in the substrate, you are guaranteed an attractive pop of color in your tank. Because it’s a tall plant, it will take your tank to another level, giving it a new dynamic, with the way it sways in the water’s current. It can be mesmerizing to watch!

Besides the aesthetics, adding hornwort to your tank has other vital advantages. Because hornwort is a plant, it will photosynthesize, producing oxygen in your tank that supports your fish and helps to keep them healthy. 

Because of its need for lots of nutrients and its fast growth rate, hornwort is known as a nitrate buster. It will help you keep your tank’s water values constant and stable, protecting your fish from spikes in the nitrate levels and other damaging compounds between water changes and maintenance sessions.

Hornwort also provides areas for your fish to hide and shelter when they are trying to escape harsh lighting or even other fish. This plant is also an excellent option for creating a nursery for your fry. Java moss is a good option as well.


Although it has the look of many plants bunched together, one plant will actually have several stems. The hornwort doesn’t really have an actual root system, but it does have leaves that will help to anchor the plant in your tank’s substrate. It can also grow hair-like roots called rhizoids that will help to anchor your hornwort in the substrate, as well. 

Without trimming and pruning, your anchored hornwort can grow all the way up to your tank’s surface, sometimes with as many as three branches per node. Amazingly, in its natural habitat in the wild, it can grow up to 10-feet tall with a diameter of 1/10 inches.

The hornwort’s leaves are similar to needles and grow in groups of six whorls, with as many as twelve whorls. Although they will fork one or two times, they will still remain somewhat shorter, usually less than an inch.

Hornwort is usually a vibrant darker green plant, although, in warmer climates, it can appear lighter. 

The hornwort will flower during reproduction. As a monoecious plant, the female and male flowers can be found on the same plant. The flowers are brown and small, around 1/10 of an inch long. The flower will also produce a fruit, or nut, about 1/5 of an inch long, that has three spines.


Tank Requirements( Lighting, Temperatures, Water, etc.)

In the wild, you can find hornwort in different structural environments, such as marshes, ponds, rivers, and lakes. Because these natural habitats have such a broad scope, designing your tank is simple. The hornwort doesn’t have any right way or wrong way to set it up. As long as you take care of it properly, it will stay healthy.

Hornwort can work in any size of tank you choose. In the smaller tanks, you can prune it on a regular basis to keep it contained. Ideally, 15-gallons is the lowest you should go in tank size because of its rapid growth rate. In the larger tanks, you can let it grow as big as you want, pruning it back when it reaches the size you want it to be. 

This plant does quite well in a wide range of temperatures, from 59-86°F. Because of this, hobbyists will plant it in both tropical and cold-water setups. The pH levels have a wide range as well, from 6.0 to 7.5. The hardness should be in the 5-15 dGH range.

Although there aren’t any special requirements for the filtration system, you still need a system in place to keep the nitrates, nitrites, and ammonia levels low. 

When it comes to lighting, they are a little needy. The hornwort needs a higher light intensity for photosynthesis and growth purposes, as well as clear water so the light can penetrate through the tank water to the plant.

You will want to change the water out on a regular basis to keep the water clean. You do not have to replace all the water, only partially. If you have other plants in your tank along with the hornwort, you might consider adding fertilizer to the water change each week because your hornwort will steal all of your tank’s nutrient supplies.

Planting Hornwort

Hornwort is actually a very flexible plant. Because the hornwort doesn’t have actual roots, it works perfectly as a floating plant. However, it does have the ability to lodge itself in the substrate with modified stems for anchoring it in place.

Floating Hornwort

As a floating plant, all you need to do it drop it in your aquarium, and it will take care of itself. From time to time, you will have to prune it back to keep it from overtaking the surface of your tank’s water. If this happens, everything under the hornwort may suffer from a lack of light.

Anchored Hornwort

If you would rather have your hornwort in the bottom of your tank, you can try anchoring it in the substrate. However, this can be a bit challenging in some situations, especially if your hornwort has not grown “anchors” yet.

You want to anchor them into the sand or gravel carefully because if you just shove it into the substrate, you could damage the stems, and they won’t grow well for you anymore. The same goes for burying the stem too deeply in the substrate, as well. 

One trick that many aquarists are turning to is the use of suction cups to hold the stems in place until they become firmly anchored. It’s not necessarily pretty to look at, but it will keep them in place without damaging the stems.

You can use the suction cups that are used with the aquarium heaters. If your plants don’t become firmly anchored, you can continue using the suction cups. Eventually, the plants will propagate and cover up the unsightly suction cups, so you don’t see them anymore.

Care & Maintenance

Some aquarium hobbyists have some difficulties getting their hornwort to start growing, but once it does, it is pretty hard to kill. Your goals for growing your hornwort will determine how much maintenance is needed. 

If you want a lot of greenery in your tank or you are growing it in your breeding tank, you can pretty much leave it alone, pruning it back only when you deem necessary. But if you are growing it for beautification purposes, you might need to do a little more work to keep it looking nice. 

As we’ve mentioned previously, hornwort grows quickly and can overtake your aquarium in no time. If you’re floating them, they can quickly overtake the surface of the water and start depriving any plants and fish underneath them of needed light. 

If you have anchored hornwort and it grows to the point of taking over the water surface, it will affect the lower parts of the stem that aren’t getting the light they need. These lower parts will turn brown and start shedding leaves, leaving bare portions on the stems.

If you don’t like the way that looks, you should make sure that you prune the hornwort regularly so that it doesn’t overtake your tank. Don’t be shy about cutting it back. The cuttings can be used to grow new plants. Also, pruning your hornwort will force it to start growing offshoots, which will make it look fuller, denser.

Hornwort Propagation

As with most stem plants, propagation is easy. If you’re not careful, you may end up with more stems than you want because of its rapid growth rate.

In order to propagate hornwort, all you need to do is divide the stem and replant the pieces that you cut off while pruning plants that have become too tall. All it takes is a couple of weeks, and they will start growing like usual again.

Because of how easy this process is, you could very easily and quickly grow a hornwort forest for your aquarium, plus have some leftover to give away, sell or use as compost.


Tank Mates and Compatibility

Hornwort is compatible with most fish. Some fish do better with hornwort in the tank with them. Live-bearers get the most benefits from hornwort. Guppies and Common Mollies use this plant as a shelter for fry after mating. 

Angelfish and Gouramis use hornwort as a food source. Loaches and other scavenging fish, as well as shrimp and snails, will clean up the debris that the hornwort sheds, keeping the aquarium floor clean.

Common Problems with Hornwort

There are a few things you can check if you start having problems with your hornwort. First, has the plant recently been moved? A lot of plants don’t like to be moved, changing their environment or conditions. 

If your hornwort was indeed moved recently, within a few weeks, you should give it a little time to acclimate itself to the new spot or environment. As long as your tank is well balanced, hornwort should adapt quite well. If it doesn’t adapt well, there are tips below that you might find helpful.

Losing leaves

A matured, adult hornwort stem with shoots coming out of the sides can sometimes look like a Christmas tree. And, it can sometimes shed like one too. But don’t worry, some shedding is expected. However, if your plant starts looking sparse, like Charlie Brown’s Christmas tree, there may be something else happening.

Turning yellow

Yellowing hornwort can be an indicator of several different problems. Pinpointing the correct one can be challenging. The first thing you need to do is check your tank, make sure that everything is at the proper levels, and nothing is off. Test the water to see if there is a nutrient deficiency or a lack of iron.

Make sure your plants are getting plenty of light. If you have a lower light tank, you will do better to float your hornwort rather than anchoring it in the substrate. Floating will help it get plenty of light.


Just like with yellowing, it can sometimes be challenging to discover why your hornwort wholly melted away in just a couple of days, leaving behind a terrible mess. Once again, you need to check all of the water parameters to make sure all the levels look good. 

Also, did you change or add anything to the aquarium right before the melt started? Some have noted in the aquarium trade that hornwort can be somewhat sensitive to liquid carbon. 

Another thing to consider is whether you have moved the plant recently. There are times when moving the hornwort will cause it to stress, and it will begin to decay. Once that happens, you can’t stop the decay. Remove that plant as quickly as possible from your tank.

Turning brown

Don’t be fooled into thinking there’s a problem because the tips of your hornwort start turning brown. They are supposed to turn brown! When hornwort is healthy and gets an abundance of light, it will take on a brownish or reddish color.

Is Hornwort Suitable for Your Aquarium

Because of its undemanding nature and its hardiness, it is suitable for most aquariums. The hornwort makes an excellent aquarium plant choice for beginner hobbyists. It’s a multi-functional plant, keeping young fry safe while keeping algae levels and fish waste at a reasonable level.

Surface-dwelling fish love when it is used as a floating plant, while the lower level fish use the planted hornwort as shelter. You need to be committed to regular trimmings of the stems in order to keep it from overtaking your aquarium. Otherwise, hornwort will make a beautiful addition to your tank.

Michele Taylor
Michele Taylor

Hello, fellow aquarists! My name is Michele Taylor, and I am a homeschool mother of six children, which includes five boys and one girl. My kids range in age from five-years-old to eighteen-years-old.

Growing up, our family had a large aquarium with angelfish, goldfish, and lots of different varieties of neons. We also had a “suckerfish” that grew to be about six inches long.

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Michele Taylor
Michele Taylor

Hello, fellow aquarists! My name is Michele Taylor, and I am a homeschool mother of six children, which includes five boys and one girl. My kids range in age from five-years-old to eighteen-years-old.

Growing up, our family had a large aquarium with angelfish, goldfish, and lots of different varieties of neons. We also had a “suckerfish” that grew to be about six inches long.

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