Overview: Ceratophyllum demersum 'Foxtail' is also popular as Hornwort. It is a popular freshwater and unique aquarium plant that grows very fast. Ceratophyllum exhibits over 300 species, but Ceratophyllum demersum is the most common among all. It is an undemanding plant, therefore suitable for beginners too. Due to Foxtail's fast-growing and undemanding nature, it is recommended for initial planting and breeding tanks as it helps build the confidence of new aquarists. Foxtail is rootless, free-floating plant and is believed to be found in a smaller tributary in Bolivia during an expedition to Rio Guapore, a boundary river between Brazil and Bolivia.

Appearance: Even though Ceratophyllum demersum is a rootless plant, it is possible to plant it at the bottom of the tank. Leaves and rhizoids help anchor the plant in the substrate. Generally, one plant adorns many stems, giving the look of multiple plants. At the same time, leaves grow dense and compact, giving an attractive appearance. In the natural habitat, Foxtail can grow up to 10 feet long and 1/10 inch in diameter. Typically, the color of the plant is dark green, though, in warm conditions, lighter green shades occur too. 

Hard/Soft Plant: Ceratophyllum demersum 'Foxtail' is a hard plant.

Ideal water temperature: The ideal water temperature ranges between 15 and 30 degree Celsius. 

Lightening conditions: Moderate lighting is enough to help Foxtail attain good growth. 

Ideal pH level: This plant stays comfortable in the pH range from 6.0 to 7.5, while hardness should be 5-15 dGH.

Propagation: In the wild, Foxtail grows easily through vegetative propagation. In this plant, the main step grows multiple side shoots that get detached over time and become a whole new plant. If you want to multiply Foxtail in your aquarium, try cutting off a side stem and planting or floating it elsewhere. Over the next couple of weeks, this should develop as a new plant.

Other requirements: 15 gallons should be the minimum tank size, or the plant may quickly get out of control with its fast growth rate. Regular trimming is essential to control the growth of Foxtail. 

Do you know: Due to rapid growth habit, Ceratophyllum demersum 'Foxtail' becomes too large and begins to dominate the tank. Therefore, it is essential to keep pruning them, or else they cover the entire surface and prevent light from reaching the lower surface of the tank.