Riccia is a naturally floating aquatic plant also known as crystalwort. Used as an aquarium plant, it can be floated on top of the water in the tank or anchored down with driftwood or rocks to create a carpet. It's very easy to grow, needing no substrate or soil of any kind, and can be a life-saving protective covering for baby fish. Riccia is found naturally all over the world and is gaining much popularity for its use in aquascapes. Riccia is not normally used in outdoor water features or ponds due to the extra maintenance and invasiveness of the plant.
Push a handful-size clump of riccia down under the top of the water in your aquarium. You will see duckweed floating out of the riccia and coming to the surface. Scoop up the duckweed and discard.
Allow the riccia to remain as a floating plant at the top of the tank to act as protective cover for baby fish. Keep the tank light on as much as possible if you want the riccia to grow.
Tie a piece of riccia to driftwood by wrapping a piece of fishing line around it to hold it on. Leave a piece of the plant hanging free from the fishing line. This piece will act as cover for the babies, while the tied down piece will grow and look like moss covered wood.
Place a piece of riccia over a rock or piece of slate. Wrap nylon mesh over the plant and the rock. Pull the mesh tight on the bottom of the rock and tie off with a twist tie. Place the rock at the bottom of your tank. In time, the riccia will grow and you will not be able to see the mesh.
Fertilize the riccia if you want faster growth by putting in stronger lights and giving the water CO2 injections. This will require extra tank maintenance, so you may want to allow the riccia to grow slowly.
Keep plant-eaters in your tank to a minimum or they will eat the plant as quickly or more quickly than it will grow. This includes some algae eaters, so inquire as to what they like to eat before you purchase them.
Trim the riccia occasionally so it does not take over too much room in the tank. Especially when left floating, the plant will grow thick and down, giving your fish less room to swim and blocking the light from the water.