Riccia fluitans is a freshwater aquatic liverwort widely used in aquascaping due to its bright green coloration and ability to form dense, bubbly mats under high light conditions. Unlike most aquarium flora, Riccia naturally lacks true roots, relying instead on small, hair-like structures called rhizoids for slight surface adherence when floating. Because of this buoyancy, achieving a popular submerged look, such as a carpet or attached growth on hardscape, requires mechanical assistance. The techniques for fixing this plant differ significantly from planting rooted species and depend on the desired aesthetic.
Preparing the Plant Material
Before any attachment method can be used, Riccia must be properly handled and cleaned to ensure successful growth and prevent contamination. Gently rinse the plant material under a slow stream of water to dislodge debris, algae, or microscopic hitchhikers. This cleaning is important because contaminants secured beneath the attached mat will be difficult to remove later.
When preparing the material, large, thick clumps must be separated into thin, uniform layers, only a few millimeters thick. If the layer is too dense, light cannot penetrate the lower portions of the mat. The shaded cells will quickly die off, leading to decay and the eventual detachment of the entire piece. A uniformly thin layer ensures light and water circulation reach all parts of the liverwort, promoting healthy, submerged growth.
Securing Riccia Using Mesh or Netting
The use of mesh or netting is the most common and effective technique for creating a broad, uniform carpet of Riccia on the aquarium floor. This method involves sandwiching the thin layer of prepared liverwort between a flat, non-toxic weight (such as a slate tile or lava rock) and a fine mesh material. The mesh should be aquarium-safe, with stainless steel or plastic grid material being durable options.
The thin mat of Riccia is spread evenly over the surface of the chosen weight. A piece of mesh is then placed directly on top and secured tightly to the weight using thin nylon string or plastic cable ties. This mechanical pressure holds the plant firmly against the substrate, preventing its natural buoyancy from causing it to lift and float.
Over several weeks, the Riccia will grow through the small openings in the mesh, forming a dense, self-supporting cushion. Once the growth is robust and thick, the mesh is completely obscured, creating the illusion of a naturally rooted carpet. This technique is advantageous for large-scale aquascapes where wide, continuous ground cover is desired.
Attaching Riccia with Thread or Superglue
Using Thread
While mesh is ideal for carpeting, thread allows for more precise placement on various hardscape elements. Attaching Riccia to irregularly shaped surfaces like driftwood or porous rock is best achieved using fine cotton thread or monofilament fishing line. Small portions of the liverwort are placed onto the desired location and then tightly wrapped multiple times with the thread to hold them in place.
Choosing a thread material that naturally degrades, such as plain cotton, is helpful. By the time the thread dissolves, the Riccia should have grown into a stable, self-supporting clump. The wrapping must be secure and close, as the plant does not penetrate the hardscape with roots. Stability relies entirely on the mechanical grip of the thread until the mat grows dense enough. This technique is often used to create bright green accents or moss-like patches on specific points of interest.
Using Superglue
For smaller, more delicate placements, cyanoacrylate-based superglue offers a rapid and localized attachment solution. This type of glue is considered inert and aquarium-safe once fully cured underwater. When using this technique, the Riccia and the attachment surface must be slightly damp, or briefly dried, to allow the glue to properly bond.
A small dab of gel superglue is applied to the hardscape, and the Riccia is pressed firmly into the adhesive for a few seconds before being submerged. This method is effective for attaching tiny amounts of the plant to vertical surfaces or the tips of branches where wrapping with thread would be impractical.
Maintaining Attached Growth
Once Riccia is successfully attached, long-term maintenance focuses on regular trimming to ensure the mat remains fixed and healthy. The plant exhibits vigorous growth under optimal conditions, including high-intensity lighting and supplemental carbon dioxide.
As the mat thickens, the lower layers become starved of light and circulation, leading to decay. If the mat grows too dense, the lower, shaded portions die and decompose, creating a layer of dead material between the live surface and the securing mechanism. This decomposing layer weakens the attachment, causing the entire mat to detach and float.
Trimming should be performed frequently, ideally every one to two weeks, using sharp scissors to remove the top third of the growth. This regular pruning encourages lateral growth, maintains the bright green color, and prevents the formation of the dead layer at the base. The trimmed portions can either be removed from the tank with a net or collected and re-attached to start new growth in another location. Consistent management of the mat’s thickness is the single most important action for maintaining a permanent, submerged carpet or attached feature.