Join Date: Jul 2010
Location: Outside Philadelphia, PA
As I recall, there are two varaties of watersprite. One as shown by the op and another as shown by the previous post. Both grow about the same, and can really take over the surface of a tank. It can form a mat a few inches thick, really blocking light and gas exchange, so it shoul be thinned out from time to time.
As a historical note, at one time, in the 1950's and 1960's, watersprite was considered the ideal plat to use in fancy guppy tanks, because it grew so easily. The theory was that if the plant did well, so would the guppies.