Fontinalis antipyretica, commonly known as Willow Moss or Water Willow Moss, is a popular aquatic moss species often used in aquariums and aquascaping. It has a unique appearance and provides several benefits to aquatic environments. Here is a detailed description and care guide for Fontinalis antipyretica:

Description:

Fontinalis antipyretica is a dense, branching moss that forms intricate green structures in the water. It has long, thin, and slightly curved stems with small, triangular leaves arranged in a spiral pattern. The moss has a feathery and delicate appearance, creating a natural and appealing aesthetic in aquariums. It can attach itself to various surfaces, including rocks, driftwood, and aquarium decorations.

Care Guide:

Lighting: Fontinalis antipyretica can thrive in a wide range of lighting conditions, but moderate to high light levels are ideal. If growing in an aquarium, provide at least 2-3 watts per gallon of full-spectrum light.

Water Parameters: Maintain a water temperature between 15-26°C (59-79°F). The pH level should be slightly acidic to neutral, ranging from 6.0-7.5. Fontinalis antipyretica can tolerate a wide range of water hardness.

Substrate: Although it can attach itself to various surfaces, providing a substrate like fine gravel or aquarium soil can help anchor the moss. Alternatively, you can use fishing line or a mesh to secure the moss to desired surfaces.

Nutrient Requirements: Fontinalis antipyretica is not a demanding plant when it comes to nutrient requirements. It can benefit from occasional supplementation with liquid or root tab fertilizers containing trace elements. Carbon dioxide (CO2) supplementation is not necessary but can enhance growth if desired.

Water Flow and Oxygenation: Moderate water flow is beneficial for Fontinalis antipyretica as it helps distribute nutrients and prevent stagnant conditions. Ensure proper water circulation by using a gentle water pump or positioning the moss in areas with adequate water movement.

Propagation: Fontinalis antipyretica is easily propagated by separating sections of the moss and attaching them to desired surfaces. Simply divide the moss into smaller portions and attach them using fishing line or mesh. Over time, the divided portions will grow and spread, creating a lush and dense appearance.

Compatibility: Fontinalis antipyretica is compatible with various fish and invertebrates, providing them with shelter and a natural environment.
It also helps maintain water quality by absorbing excess nutrients and reducing algae growth.

Note: Regular maintenance is required to control the growth and prevent the moss from overtaking the aquarium. Pruning and trimming can be done periodically to maintain its desired shape and prevent shading of other plants.

Overall, Fontinalis antipyretica is a beautiful and versatile aquatic moss that adds a natural and captivating element to aquariums. With proper lighting, water conditions, and care, it can thrive and enhance the aesthetics of your aquatic environment.