On Thu, 27 Aug 2009 07:55:05 EDT, Jim Hurley
wrote:

Your open space is doing better than the economy, although both are
moving ahead. Has the duckweed become more packed or is there death
at the margin of the open space?

There is some discoloration of the duckweed around the edges. It's
only a couple of centimeters wide, however, and I don't know if it's
dying duckweed or just debris that collects at the edge.