Last update: October 13, 2021

Hornwort: A Great Looking Coontail For Your Tank

If you’re looking for a good aquarium plant, the common Hornwort could be for you. It’s a great addition to any fish tank set-up, helps with oxygenation, is a beautiful piece of decoration in your tank, can help clean the water, provides shelter for smaller fish or even inverts, and does so much more.

If you’re a beginner at fishkeeping or aquariums in general, you should try the Hornwort plant. It’s easy to maintain, easy to grow, doesn’t require much attention at all, and can also survive practically anything. So if you’re someone with a black thumb, that could be the perfect plant to add to your aquarium set-up.

The Hornwort plant is great for planted tanks and aquascaping, whether you’re new to the world of aquariums or you’re already a pro. Not only is it practically impossible to kill, but it also looks beautiful and has a very unique look due to its horn-like needles. So it’s a great-looking coontail for your tank, and the price of this resilient plant is more than reasonable.

Let’s dive in and find out more about this aquarium plant, how to care for it, its tankmates, compatibility, and if it’s the right plant for your aquarium.

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Is Hornwort A Good Aquarium Plant?

General Overview

The Ceratophyllum demersum, aka the Horwnort plant, is definitely a good aquarium plant. It’s easy to care for and comes from the Ceratophyllaceae family. It’s the go-to option if you want to have a plant in your aquarium, as it’s readily available and not too expensive.

It’s very easy to distinguish the Horwnort plant from other aquarium plants or aquatic plants in general. As said above, it has horn-like needles/leaves and looks a dark yellowish-green. It can also look lighter green if it’s in a warmer environment.

 It also has multiple slender and long stems which support those leaves, which can make it look like several plants. In fact, needles (or leaves) are produced by six or 12.

This aquatic plant doesn’t have any true roots, but some leaves can help anchor the plant down, giving it a root-like structure, and it can even grow rhizoids, which look similar to hair roots. You can either choose to plant it or just let it float.

An important thing to know about the Horwnort plant is in terms of plant reproduction is that it’s a flowering plant. Not only is it a flowering plant, but it’s also a monoecious plant, which means that it has both female and male reproductive organs. So you can see both genders on this plant.

Benefits Of The Hornwort Plant For Your Aquarium

The first reason why the Hornwort is a good aquarium plant is purely aesthetic. It looks beautiful in tanks and adds a nice bit of color, both when it’s floating at the top or even when you decide to ground it in the substrate.

Then, another benefit of having a Hornwort plant in your aquarium is that it creates more oxygen, which oxygenates the tank for your fish. That’s because of this plant’s photosynthesis.

 The Hornwort plant also sways the current, so it gives the water current in your fish tank a new dynamic. Plus, it improves the water’s quality overall. That’s because it produces more oxygen and keeps the water clean, acting as a natural filter, ingesting nitrogen compounds as well as some debris that fish leave behind.

Not only that, but the Hornwort plant can also serve as a hiding spot for your fish and invertebrates. It’s great shelter for if your fish want to hide from the light, from other fish, or just serve as a protective space for when a fry is growing up. So if you’re looking for an alternative to java moss to create a safe space for your fry, the Hornwort plant is great.

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How To Care For A Hornwort Plant

Now that you know that the Hornwort plant is a good aquarium plant, as well as having so many benefits, let’s talk about how to care for this plant. This way, you can see how easy it is to care for it, and hopefully, you’ll want this great-looking coontail for your tank!

First, the pH level in your tank should be between 6 to 7.5, which is really standard in aquariums, so you know most fish will be able to live in these conditions. As for the water temperature, it should be between 59 to 86 degrees Fahrenheit, which is suitable for both freshwater fish and tropical fish. Finally, the water hardness should be anywhere between 5 to 15 dGH. Of course, keep your water clean, but that goes without saying.

The Hornwort plant is so hardy that it can resist pretty much anything, so it really isn’t fussy about the water conditions or its tankmates. So that’s why the water ranges are so wide. It’s good to add fertilizers if you want, although it’s not particularly necessary. If you do use fertilizer, you should add it to the tank about once a week, so it can get all the nutrients it needs.

Finally, you will need to give this aquatic plant light, as all plants necessitate light to be happy and grow. It doesn’t need much light and can survive on a very small amount of it. You won’t need to worry about it much, especially if you keep your plant floating. If you plant it, you need to make sure it has enough light.

As you can see, this plant is very low-maintenance. Now, let’s dive in a bit more and answer some of the questions that most people have when considering getting a Hornwort plant for their aquarium.

Can Hornwort Grow Floating?

Since the Hornwort plant is an aquatic one, you might wonder if it can grow floating. This plant actually grows better floating. That’s because it has a better access to light and C02 from the air. And it’s very easy to let it float, as it floats naturally, without you having to do anything.

However, it’s also possible to grow it by rooting it in the bottom of your fish tank, in the substrate, or even attach it to a hardscape. It’s a matter of personal preference. If you let it grow floating, it will be great for surface-dwelling fish. If you prefer to let it grow rooted at the bottom of the tank, bottom-dweller or middle-dweller fish will love it. So it depends on what kind of fish you have, and what you want for them.

As for the temperature the Hornwort plant needs to grow and survive, it should approximately range between 50 to 85 degrees Fahrenheit. As you can see, this is not a really hard requirement, like most fish, and particularly freshwater and tropical fish will necessitate that temperature anyway.

This means you can put and grow this plant in a cold water fish tank with no heater, a tropical fish tank, and even outdoor ponds. This aquatic plant is really adaptable and easy to care for. The only real thing you need to watch out for with a Hornwort plant is that you need to trim it pretty regularly so that it doesn’t limit gas exchange or block the light too much in the tank for your fish.

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So the Hornwort plant is really versatile. It can grow floating or rooted to a substrate. It’s up to you. If you decide to let your plant float, it’s very easy. You literally just drop it in your fish tank and let it do its own thing. It will naturally grow floating. 

That’s how amazing this aquatic plant is. In fact, it will grow very rapidly. So you’ll need to manage it and prune it, as it can block the light very quickly, instead of just creating a light shade.

If you decide to plant your Horwort plant, that’s a bit more difficult, but it’s doable as well. Since this aquatic plant naturally wants to float towards the surface, you will need a bit more effort to plant it.

What many people do to prevent your Hornwort plant from floating is to pin it down with suction cups (yes, you read that right). You need to pin the aquatic plant at the base of its stem to the bottom of your aquarium. That won’t hurt the plant, and it will make sure that the Hornwort plant is planted and anchored.

Does Hornwort Produce Oxygen?

Next, you might wonder if the Hornwort plant produces oxygen. As stated previously, this aquatic plant photosynthesis, which produces oxygen. This aerates the water tank and gives more oxygen to your fish, which improves their quality of life. That’s because they can use this oxygen, which was produced by the photosynthesis of the plant, to breathe.

So that’s another great benefit for your aquarium!

Does Hornwort Need CO2?

Another question you might have is if the Hornwort plant needs C02. Well, it doesn’t; it’s not mandatory. However, you can decide to give your plant C02. It can act as a fertilizer to help your plant grow better, but it’s really not necessary, considering that it grows very easily and naturally without much outside help.

If you decide to use CO2 as a fertilizer for your Hornwort plant, you need to be careful as high levels of it can be extremely dangerous for some invertebrates such as shrimp, for example.


Finally, let’s talk about propagation, and what to do so you can propagate the plant. Don’t worry. It’s very easy. The Hornwort plant propagates by vegetative fragmentation, which is a very common method for invasive plant species in particular.

How it works is that basically, a tiny part detaches itself from the base plant, the so-called ‘parent plant’, to then form a new, independent plant. Then, the main stem of the plant will grow several side shoots. If you plunge the stem into the fish tank, the growth will continue.

You can also choose to propagate your Hornwort plant in your aquarium actively. Just remember that it spreads very quickly, and can block light and space for your fish or invertebrates, as it can take up the size of your tank, no matter how small or big it is, very quickly.

What you need to do if you want to propagate your Hornwort plant is you need to cut off the stems and leave them to float at the surface of the water, which they will naturally do. You can simply use cut stems from the previous trimming. Then, these stems will grow into an individual new Hornwort plant. 

As for how you should cut the stems, there’s no specific way you should do it. You can just cut a couple of parts, two or three, and your plant will survive. This plant can basically survive anything, so don’t worry if you’ve got a black thumb. It’s really easy to take care of it and propagate it if you choose to.

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Tank Mates And Compatibility

In terms of tank mates and compatibility, the Hornwort plant will pair with about any fish, but there are some fish that will benefit more than others. The benefits will vary according to which fish species you’re referring to.

This is the case for live-bearers, fish such as Guppies or Mollies, who will go in the plant to mate and then keep the fry there until it reaches its full maturity and is big enough to fend for itself. They can also use this aquatic plant for egg-laying or even hiding.

As for fish species such as Angelfish or Gouramis, they can eat the Hornwort plant, as it’s a good food source for them. You don’t have to worry about them damaging the plant or other fish eating it since the leaves of this aquatic plant are pretty hardy, which makes it pretty difficult to eat.

 Some other fishes and invertebrates will help the plant and the overall health of the fish tank by clearing debris sheds from this aquatic plant, which it can leave behind. That’s probably the only disadvantage of the Hornwort plant.

This won’t even be a problem since these invertebrates or fishes such as shrimp, snails, and scavenging fish such as loaches will clear up the debris from the Hornwort plant. This means that your fish tank will look cleaner. 

So this plant is a win-win in terms of tank mates and compatibility. It fits every fish, invertebrate, and aquarium. Some more than others. It’s best to put it in community tanks with both fish and invertebrates so that it can benefit the fish, and the invertebrates can help keep the aquarium clean.

Is The Hornwort Plant Suitable For Your Aquarium?

Whether you’re a beginner at the aquarium world or an expert, the Hornwort plant will be suitable for your aquarium. It doesn’t matter what fish you have, if you have invertebrates, or if you have both. This aquatic plant will be compatible with every tank mate.

The Hornwort plant can be a refuge for many fish, whether it be for hiding, for mating, for egg-laying, or to keep fry safe. You can also either keep this plant floating at the surface of your fish tank, or you can have it rooted at the bottom of your tank in the substrate. If you keep the Hornwort plant floating, it will be great for surface-dwelling fish. On the other hand, if you decide to have it rooted, it will be great for fish who like to stay at the bottom.

It’s sturdy, pretty impossible to kill, looks pretty, improves the oxygen amount and quality in the tank, as well as the water, as it acts as a natural filter. There are only advantages, and you will be able to take care of it easily, whether you have a black or green thumb. You will just need to commit to trimming the stems regularly so they don’t invade the whole tank.

Final Thoughts

The Hornwort plant is definitely a great-looking coontail for your tank, which has so many benefits for your aquarium, your fish, and your invertebrates. It is also a cheap option, easy to care for, practically unkillable, that is available at most stores, and is very popular as well.

This aquatic plant is suited for any fish, invertebrate, and pretty much any tank there is, whether it be a tropical fish tank, a freshwater fish tank, or even a fish pond. This plant is great as it releases oxygen into the tank, can provide shelter for your adult fish or fry, and can provide a mating and egg-laying spot. 

It also looks beautiful and improves the overall water quality of the aquarium. Plus, it’s very easy to maintain, acts as a natural filter, and you can choose to plant it or let it float. So if you’re a beginner in the aquarium world, this is probably the best plant to start with!

Ian Sterling

Ian Sterling, founder of, began his aquarium journey over 30 years ago, driven by a deep fascination for fish and their diverse personalities. His website,, is dedicated to making fishkeeping accessible and enjoyable, offering beginner-friendly guidance, expert insights, and a community for aquarists to connect and share experiences.

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