Hornwort: Care & Propagation Guide

Hornwort (Ceratophyllum species) is a widely available aquarium plant that can be found in most pet stores. You might see this plant labeled as hornwort, coontail, or coon’s tail plant in your local pet store. 

This plant is hardy and beginner-friendly that can grow in any tank conditions. Because they are free-floating types of aquarium plants, they do not need any special substrate. This makes them a super easy plant to maintain. 

Despite being hardy, hornworts need a specific environment to be able to survive and grow. In this guide, we are going to point out all the important steps you need to take in order to keep your hornwort plant safe and sound. So keep reading.


The Hornwort or coontail plant is a relatively large stem plant that grows natively all around the world. They can grow up to 10 ft long stems and each stem can have multiple stems shooting out from the main stem. 

There are many variants of Ceratophyllum (Hornwort aka coontail) that naturally grow in different parts of the world. But the most famous variant in the aquarium hobby is “Ceratophyllum demersum”.

Hornworts grow naturally in areas where water is still or with a slow to moderate current. This plant can not survive in fast-moving rivers and streams as the water will break its fragile stems. 

This free-floating aquatic plant grows super fast and bushy. This makes them an ideal plant for fry tanks. Breeders keep this plant in their aquariums to remove excess ammonia or to provide hiding spots for the fish fry. 


Hornwort Plant

Hornwort is a root-less free-floating aquatic plant that grows leaves from a central stem. This makes it look like a raccoon’s tail which is why some call them “coon tail”. 

Hornwort develops lush green colored leaves that stay bright green when they receive enough light. Leaves develop 6 – 12 needle-like whorls that circle the main stem. The leaves are small and only grow to about an inch. 

If they are left unpruned, they will shoot numerous side stems from a central mother stem and create a bushy mass. They can free float in the water or stay on top of the tank for maximum light absorption. When they receive enough light they will rapidly shoot new stems and grow into large plants.

Size & Growth Rate

Hornwort in an aquarium can grow up to 2 feet. In the wild or in larger tanks or ponds, they can grow up to 10 feet.

Because they are very fast-growing species they can reach their maximum size in a matter of weeks. When light and nutrition are sufficient, they usually grow about 2 inches per week. This makes them one of the fastest-growing species of aquarium plants. 

Hornwort Care

Hornwort care is a piece of cake. As long as you provide them with a strong source of light they will grow without any problems. The fish waste in the tank is usually enough for this plant to thrive. 

However, when there is an imbalance in the tank, this plant can create a mess. When they receive less light or nutrition they will start to break down and release their dead leaves into the tank. This can make your tank look ugly and cause ammonia spikes as dead leaves rot. 

To ensure this never happens in your tank, you will need to follow all the basic requirements this plant needs. 

Tank Size

The ideal tank for hornwort is 20 gallons or more. Hornwort is a tall plant but because they are water column feeders and stem plants you can keep them in smaller tanks. If you keep them in a small tank you will need to prune and trim them more often as it will quickly fill your tank. 

We have grown Hornworts in almost all sizes of aquariums and our experience they grow best in larger tanks. In smaller tanks, they tend to grow more stems and in tall tanks, they seem to grow single tall stems. This is probably due to the fact that the plant tries to reach the light source as fast as it can. 

Hornwort Plant

Water Conditions 

Hornwort is hardy and can live in most tank environments. They need a strong source of light to maintain their structure and firmness. 

This plant appreciates a slow-moving water current but a decent amount of water circulation is needed to remove debris from the plant. Make sure not to use powerheads or strong filters that can push or break the stems. This can cause the plant to die.

The tank needs to be stable and well cycled as well. A good filter is necessary to make sure fish wastes can break down to usable nutrition for your hornwort. 

The ideal range of water parameters for hornwort is mentioned below. However, they can also survive in a wider range but will not thrive. 

  • Temperature: 65 – 85 Degrees Fahrenheit 
  • PH: 6 – 7.5
  • TDS: 60 – 250 PPM

Hornwort can tolerate colder water as low as 50 degrees Fahrenheit. This makes them a great plant for cold water aquariums. However, at low temperatures, they will grow slowly and develop darker and ugly-looking leaves. 

CO2 Requirement

Hornworts do not need CO2. However, like all aquatic plants, they will grow much faster when they receive CO2. 

CO2 will cause the plant to stay lush green and grow rapidly. It can also prevent the stem or leaf from melting and rotting. 


Hornwort needs strong lighting conditions. This plant needs a full spectrum of light to be able to keep its integrity. 

For short periods, they can survive low light conditions but they will start to melt if they are left in a low to medium lighting environment for a long time. 

A 6700k full spectrum light is the ideal type of light for Hornworts. If you have a balanced aquarium with enough fish in it you can keep the light on for 6 – 12 hours daily. If you notice algae growing on your hornwort, you can lower the hours that light is on until you find the right balance for your aquarium. 


Hornworts do not need substrate. This plant does not produce roots, instead, it absorbs nutrition from the water column. You can leave the plant floating in the tank or tie it to objects so it stays in place. 

Planting & Placement

Hornworts are tall and bushy plants so they might not be the best type of plant for a well-aquascape tank. However, it is definitely possible to keep them in an aquascape as long as you do your regular maintenance. 

Generally, this plant is left free-floating in shrimp tanks or fry grow-out tanks. But if you want to keep them in your display tank, then you should keep them in the background. This is because they will grow very tall and will block your tank’s view if placed in the front of the tank.

You can attach the plant to a rock or a piece of driftwood so it doesn’t move around. 

Hornwort Propagation

Because hornworts are stemming plants, you can easily propagate them by cutting the stem. Every time you are trimming the plant, you can tie the cuttings and leave them in the same tank or a separate tank to grow and become new plants. 

This makes this plant super easy to propagate and grow in higher volumes. This is why they are sold very cheaply and almost always available in pet stores. 

In the wild, this plant propagates the same way. When they grow enough stems, some of them will break off the main plant and will continue to grow on their own. This is why they are widely available in almost all countries in the world. 

Maintenance & Fertilization

Since Hornwort is a fast-growing plant, you will need to trim and prune it regularly. They will need a lot more maintenance than slow-growing plants. So if you don’t have the time, it is probably the wrong choice of plant for you. 

However, on the bright side, you can use their fast growth rate to your advantage. Their fast growth rate means they will absorb all the nutrients off the water making your tank clean and healthy. This can help you with fighting with algae in your aquarium. 

The one thing you need to know is that Hornwort can melt when the tank conditions are not in their favor. If you see leaves chipping off the plant, that’s a sign that something is not right in your aquarium. You should immediately check your water parameters, amount of light, and amount of fertilization in the tank. 

Speaking of fertilization, horn worths do not need fertilization. The waste produced in the tank is sufficient for the plant to grow. If you have other plants that compete with your hornwort over nutrients, you can add liquid fertilization every week to keep all your plants happy.

Tank Mates

The Hornworts can coexist with most aquarium species including fish, plants, and invertebrates. But they can cause suffocation to other plants as they can float to the surface and block the light. They will also absorb nutrition much faster than other water column plants which in rare cases can lead to the death of the other plants. 

Some fish are also not ideal tank mates for hornworts. This plant is fragile and can easily break, so avoid adding them to a tank that has nippy fish. 

This plant can make a great addition to livebearer fish and shrimp tanks. Because of its fast and dense growth, it will provide the fish fry with great hiding spots that will save the life of the fry. Shrimp tanks will also appreciate the extra surface this plant will provide them. 

Here are our top pics of ideal tank mates for Hornworts:

Benefits of Hornwort in Aquariums

Hornwort is a beautiful and hardy plant that can create beautiful and dramatic scenes in a tank. By adding this plant to your aquarium you are adding beauty and helping your tank to stay in a healthier environment for your fish. 

It can also oxygenate the water during the day. But this is probably not the best reason aquarists keep this plant as it will use the same amount of oxygen back when lights are off. 

The main reason this plant is famous is its ability to create dense bushes that fish fry can hide from bigger fish. Most breeders have this plant in some of their breeding tanks if not in all of them. It helps the water to stay clean and gives a good refuge for fry. 

Hornwort Plant


Hornwort is an affordable hardy plant that can tolerate colder waters than other species of aquatic plants. At the same time, they can also live in tropical environments which makes them a great choice for most aquarium setups.  

When tank parameters and conditions are right his plant will rapidly grow and remove all the waste your fish generate. This makes your tank stay clean and healthy at all times.