Abundant and common species in the warm water could likely develop reduced densities. But if nutrients are present, then species adapted to cold water could easily increase in number to keep phytoplankton common or even abundant. I have seen blooms in winter's cold water and even under the ice. Light intensity and nutrients determine algae density no matter what the water temperature is. This assumes adequate alkalinity.
A common time to stop aeration is when the water gets 50F or high 40's or near these temps. Then the pond usually fully circulates especially if it receives some wind action. Fall circulation stops when ice cover forms and water is typically 39F from about 14"-20" to the bottom.
Last edited by Bill Cody; 09/26/12 06:45 PM.
