Crystalwort

Riccia fluitans forms branching green thalli that float together in loose patches. It is a liverwort rather than a rooted stem plant, and it can be used as surface cover or as a tied-down accent. The chosen method determines the maintenance: floating portions need thinning, while an attached-looking carpet needs to be kept secured because the plant does not root into the surface.

Medium to strong light supports aquarium cultivation. Added CO₂ can improve submerged growth, but the floating plant is also kept without injection. The optimum temperature is 20 to 27 °C and pH 5 to 7.5. Keep nutrients available and allow light to reach the parts you intend to retain. A thick mat may shade its own lower growth as well as other plants.

Divide a healthy portion to propagate. For a submerged cushion, hold the thalli against the chosen support with suitable mesh or line and trim as they become too thick. Collect the cut pieces before they float away and establish elsewhere. For surface use, remove surplus growth while leaving the amount of cover the tank can accommodate. Adjust thinning and trimming to the density and condition of the patch.