Japanese Takashi Amano has inspired many aquarium owners to keep the 1-5cm tall cosmopolitic moss,
Riccia Fluvitans, submerged. It can be kept down by tying it to a stone with a piece of fishing line or cotton,
but new shoots always grow towards the surface, so it may be necessary to prune it with scissors. Riccia
Fluvitans thrives best with added CO2 and in good growing conditions small oxygen bubbles form on the
leaf tips. As a traditional floating plant offers good protection for young fish.