Ceratopteris cornuta 'Horned Water Fern'

Ceratopteris cornuta, commonly known as Horned Water Fern or Water Sprite, is an attractive aquatic fern that is part of the Ceratopteris genus, known for its unique, feather-like leaves and fast growth. Unlike some other plants in the hobby, it is often grown as a floating plant, but it can also be rooted in the substrate, depending on the desired look and setup. It’s an excellent choice for both beginners and experienced hobbyists, thanks to its adaptability and minimal maintenance needs.

Care Tips for Ceratopteris cornuta (Horned Water Fern):

1. Light Requirements:

   • Ceratopteris cornuta grows best under moderate to high light conditions. In brighter light, it will produce denser, more compact growth. If the light is too low, it will still grow, but its growth rate may slow down and the plant may become more spread out and less vigorous.

2. Water Parameters:

   • Temperature: This plant thrives in tropical conditions, with an ideal temperature range of 72–82°F (22–28°C). It is quite adaptable and can tolerate a range of temperature fluctuations within this range.
   • pH: Ceratopteris cornuta does well in slightly acidic to neutral water, with a pH range of 6.0–7.5.
   • Hardness: It can grow in soft to moderately hard water and is generally tolerant of a variety of water hardness levels, making it a versatile option for many aquariums.

3. Substrate:

   • While it can grow rooted in the substrate, Ceratopteris cornuta is often grown as a floating plant. If you want to anchor it, a nutrient-rich substrate works best, and it will benefit from the added nutrients provided by root tabs or liquid fertilizers.
   • If grown floating, it will absorb nutrients directly from the water column, making it an excellent choice for tanks with higher levels of nutrients.

4. Growth Rate:

   • This fern is known for its fast growth rate. It can rapidly cover the water surface, especially when grown as a floating plant. In the right conditions, it will quickly expand, creating lush, bushy growth that helps fill up space in the aquarium.

5. Pruning:

   • Regular pruning is important if you’re growing it as a floating plant, as it can easily cover the entire surface of the tank. You can trim back overgrown fronds and allow new shoots to develop. When rooted, you can also prune it to maintain its shape and control its spread.

6. Fertilization:

   • Ceratopteris cornuta is a moderate to heavy feeder, especially if you’re growing it rooted. Liquid fertilizers with essential micronutrients and root tabs will ensure that the plant receives adequate nutrition. CO2 supplementation can further boost its growth, but it's not strictly necessary in moderate-light setups.

7. Positioning in the Tank:

   • Floating: When allowed to float, Ceratopteris cornuta will create a canopy effect across the surface of the aquarium, providing shelter for small fish, shrimp, and fry. It can also help to reduce algae growth by absorbing excess nutrients in the water.
   • Rooted: If you decide to anchor it in the substrate, it can be placed in the midground to background of the aquarium. It will grow tall, with fronds that arch outward, making it a beautiful plant for adding vertical dimension.

Interesting Facts:

1. Unique Appearance:

   • Ceratopteris cornuta is known for its delicate, feathery fronds that have a somewhat lobed or horned appearance (hence the "horned" in the common name). This gives the plant a softer, more natural look in aquascapes compared to other, more rigid plants.

2. Floating and Rooting Ability:

   • Unlike many plants that are either strictly rooted or floating, Ceratopteris cornuta can be grown in either manner. This versatility makes it a great choice for aquarists who like to experiment with plant positioning and tank design.

3. Good for Tank Health:

   • As a fast-growing plant, Ceratopteris cornuta is great at absorbing excess nutrients like nitrates and phosphates, which can help control algae and improve water quality in the tank. Its ability to filter nutrients directly from the water column when floating is one of its standout features.

4. Excellent for Shrimp and Fry:

   • Because of its dense, bushy growth, Ceratopteris cornuta provides excellent hiding spots for small fish, shrimp, and fry. It can reduce stress for shy or baby fish, allowing them to find shelter from larger tankmates.

5. Easy to Propagate:

   • This plant can be propagated easily by simply cutting off a healthy frond and allowing it to float or replant it. New shoots will grow from the cut ends, making it easy to spread the plant throughout your tank.

6. Low Maintenance:

   • Ceratopteris cornuta is a low-maintenance plant, especially when floating. It requires little intervention aside from occasional pruning, making it a good choice for beginner aquarists or those looking for a plant that thrives with minimal effort.

Fun Fact:

• Ceratopteris cornuta is a true fern, which means that it reproduces through spores rather than seeds. You might not notice it in the aquarium, but if you were to observe the plant in its natural habitat, you’d find that the undersides of the fronds contain tiny spore cases that release spores for reproduction.