You have an algae bloom occurring which can happen in winter with certain species of the cold water loving planktonic algae and if nutrient conditions are optimum for their growth. The bloom will not affect the YP providing deep snow does not block light under the ice to shade-black out light and kill all the algae due to not getting sunlight. When all the algae dies at once the bloom of bacteria attacking the dead algae, consumes all the oxygen in all the water. Do not let deep snow on all the ice for longer than 3 weeks in a new pond 15'+ deep. Keep about 10% to 25% snow off the ice.

Last edited by Bill Cody; 01/31/12 09:46 AM.

aka Pond Doctor & Dr. Perca Read Pond Boss Magazine -
America's Journal of Pond Management