The floaters main purpose is to provide surface coverage where water lilies or deep-water aquatics are sparse or absent. These may also be considered ornamental. There are two basic types. The carpeters such as Lemna and Azolla which can cover the whole surface with tiny leaves, and the non-carpeters which have larger leaves and tend to be less invasive. Planting could not be simpler as you just drop the plants in the water. Floaters will die when outdoor temperatures reach approximately 40 degrees.