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Hornwort Care Guide: How to Grow in Your Own Planted Tank 

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Hornwort is a great addition to any home aquarium and provides numerous benefits to the fish residing in the tank. It is also very unique due to its appearance of horn-like needles but is easy to care for.

Growing hornwort, or Ceratophyllum demersum, in your aquarium, requires little effort because it can float in large bunches at the top of your tank. All that is required is a water column and some time to grow. Many people add suction cups to attach the plant to the aquarium walls. 

Since the plant is so easy to grow and very resilient, it is great for beginner aquarists! By following the below recommendations you will be well on your way to having healthy hornwort plants.

Hornwort Basic Needs

As with any living being, the hornwort does have a few basic needs to meet to thrive. With that being said, this is one of the most resilient aquarium plants you can have. 

a hornwort plant Ceratophyllum demersum on a fish tank

Water Parameters


Since the hornwort is so resilient, it can live in several different water conditions. Of course, some are more favorable than others. If you would like to grow your hornwort as quickly as possible, it is recommended to have a tank temperature in between the range of 64 – 86 °F. 

However, the warmer the temperature is the faster the plant will grow. With that being said, the absolute best temperature to have your plant in is between 75-79°F. This is one of the most important factors when it comes to taking care of this plant. 

pH and Hardness

The pH is less important than the temperature when it comes to growing hornwort. Since it is found in a multitude of areas it is tolerant to a range of pHs. However, the ideal pH would be between 6.0-8.0. This can be tested weekly with aquarium test strips. 

As with the pH, the hornwort is not fussy when it comes to water hardness either. With that being said, it does tend to grow faster within the water hardness range of 3-17 dGH, but again this is not necessary. 


Since the hornwort grows so rapidly, it can quickly diminish the nutrients in your tank from the other plants and fish. This is why it is important to add supplements to the tank to ensure you have proper nutrient levels. 

You can do this by adding fertilizers to your tank on a weekly basis to make up for the lack of nutrients. You will also want to ensure you do not have too many plants in the tank and remove some if it gets too overcrowded. Also, note that the fertilizer you choose must have no copper since it is toxic to the plant. 


If you want your hornwort to grow at a fast rate, it will need to have a good lighting source. Medium-light is recommended, as opposed to high lighting. They should also have a range of 10-12 hours of lighting per day.  LED lighting is the best for maximum growth potential but is not a necessity. 

Tank Requirements

Besides the basic needs above, having the correct tank setup is just as important. This will ensure that your plants will grow to their maximum potential. 

Tank Size

As mentioned, this plant can grow very quickly so it is important to have a large tank to avoid overcrowding. With that being said, you should not place hornwort in a tank that is less than 15 gallons. Of course, the larger the better when it comes to this invasive species.

You will want to keep this plant to a minimum if you have other aquatic plants in your tank as well. It can become quickly overcrowded which can lead to the failure to thrive of other plants and fish. Always be mindful of how fast you grow the plant and propagate it if necessary. 


While some plants require a substrate to grow, the hornwort does not. The substrate can cause the plant to rot and should be avoided altogether. Instead of using a substrate to anchor the plant, you can use suction cups.

How to Plant Hornwort

Hornwort is one of the easiest plants to plant in your aquarium, as you don’t need to necessarily “plant” anything. These are free-floating plants and will do just fine when placed on the tank’s surface. However, you can have the plant growing near the bottom of the plant if you would like.

That said, you should never ground the plant into any decoration or rock. These plants do not have a typical root system, just a stem, and if you bury the stem it can die quickly. 

You can also just place the plant on a water column and wait for the plant to root or again, use suction cups to keep the plant in place. 

How to Propagate Hornwort

Since hornwort grows so quickly, you are bound to have to propagate parts of the plant eventually. This is also an easy task as well. All you have to do is simply cut off the stems of the plants you would like to move.

You will then place those stems in other parts of the tank, or a different tank completely. It also does not matter where you cut the stem on this plant. As a matter of fact, the stem can be cut into two to three parts and still survive! 

It also does not take too long for the new stems to grow into plants and you will have to start the whole process over again. This is a great plant to have if you have multiple large tanks, but again not the best for small tanks since it grows so fast. 

Benefits of Having Hornwort in Your Tank 

There is a multitude of benefits when it comes to having hornwort in your home aquariums. While you may have to trim and propagate the plant frequently to keep up with it, the benefits outweigh the hassle. These benefits include:

  • Aquascaping. Since this plant grows so fast it is excellent for decorating your tank and aquascaping. It will add personality to your tank and be just like home for many fish species. It also adds hiding places for your fish family!
  • Removes excess nutrients. As we mentioned, this plant requires tons of nutrients to grow. This means it will absorb toxins from fish waste, decayed plants, and toxins naturally in the water such as carbon dioxide. 
  • Clears the Water. If you have an overpopulation of fish, your tank can become cloudy quite easily. This plant has the natural benefit of clearing up cloudy water without the need for added chemicals in your tank!
  • Oxygenates the water. Just like other aquarium plants, the hornwort plant will naturally oxygenate the water, This will improve the life of the fish in your tank and lead to a more natural ecosystem. 
  • Reduces nitrates. Nitrates and ammonia quickly kill fish so it is important to always check the levels in the tank as opposed to other parameters. With that being said, this plant reduces the number of nitrates in a tank by up to 41% in just 10 days.
  • Reduces algae. Algae is a very common problem in most home aquariums. However, the hornwort has allelopathic properties which will reduce the growth of common blue-green algae and phytoplankton.