Some bluegreen algae Cyanobacteria can produce harmful affects to humans, animals and sometimes fish. Mostly but not always the concern is with floating scums as in the posts above. Very good idea keeping your dog out of the water. They can get sick from licking toxic algae off their fur. I am going to look at Gravinus's algae that has interesting color changes. Stay tuned for what it is.

http://www.odh.ohio.gov/features/odhfeatures/algalblooms.aspx

http://www.pca.state.mn.us/index.php/wat...gal-blooms.html

Last edited by Bill Cody; 07/07/12 01:31 PM.
aka Pond Doctor & Dr. Perca Read Pond Boss Magazine -
America's Journal of Pond Management