Moss Balls (Cladophora Aegagropila), sometimes called Japanese Moss Balls or Marimo Balls aren't actually related to moss at all. The Moss Ball is a spongy velvet-like green algae ball. These rare plants are only native to Scotland, Japan, Iceland, Estonia and now are found in Australia.
Moss Balls are great for low tech. tanks like bioBowls and other nano tanks without mechanical filtration because they actually draw in nutrients cleaning the water in the process. They don't require any special lighting or substrate. Just place them wherever you like and you're done.
For best results Moss Balls require moderate to strong levels of lighting. The temperature of the water should be between 72°-82°F, with an alkalinity of 3-8 dKH and a neutral pH.