Riccia fluitans or Crystalwort are aquatic liverworts (Marchantiales). The rootless plant grows from flat threads of tissues by branching. The plant normally grows near the surface of the water but as the clump grows thicker and heavier, it tends to sink to the bottom of the growing tank.
Riccia fluitans can be found in America, Africa and Asia. There are many biotypes but the Japanese strain is the most popular among the aquarists.The plant is a prolific oxygen producer and the oxygen bubbles get trapped for some time within the intricate branching stems giving very attractive vegetation with hundreds and thousands of gaseous pearls making it a favorite for aquascaping. Using Crystalwort is a great way to boost oxygen levels in fish tanks.nThe plant is ideal for breeding tanks both to catch eggs and to protect fries.
If allowed to grow undisturbed, Riccia will ball for use in the aquarium. The common practice is to tie some fragments of the plant in twigs, driftwood, rocks or corals. As the crystalwort grows and cover the basal item, it gives the tank a mossy appearance. Crystalworts are favorite host plant of miniature freshwater shrimps.
Culture
Riccia may easily be grown in fish tanks anchored onto rocks, wood or metal screen provided it gets good overhead lighting. Shading affects its growth. Strong water current or any form of agitation in the tanks can breaks up the branches of Riccia.
Most commercial growers use additional carbon dioxide bubbled into the tank to increase the growth of Riccia colonies. Dilute complete fertilizer with trace elements is appreciated by the plant.