Or runoff from your lawn.
Did you have any fertilizer or pesticides or
herbicides on it?
Or rapid change in the temperature of the water or just the vibration of all
the hail coming down in the water and yard surrounding (same phenomena as
pounding the ice with a hammer will do).


kathy :-)
algae primer
http://hometown.aol.com/ka30p/myhomepage/garden.html