Pond Boss Forums INTRO Questions & Observations Pond Turned Green

No.1 - Pond is in a lower area with runoff water accumulation and tree leaf additions providing annual inputs. Both enrich the pond with nutrients. These accelerate the nutrient accumulation, plant growth and overall aging process. As aging occurs, enrichment gradually increases. Increase rate depends on amount of nutrients that the pond receives each season.
No.2. With addition of ducks their activities and continual manure additions further enriches the pond to push it over the balance point of clear to green. Green is from microscopic plants that thrive in fertile water. Some of these plant species like cold water, some like cool water and some like warm water. When nutrients are "right" different species can now thrive better with higher nutrient concentrations. The pond ecosystem is responding to the build-up of excess nutrients. Duck manure is very 'nutrient rich' and the pond is showing its response to even more fertilizers. More growth and often a different type of growths. This is what fertilizers do - makes plants green to grow better and maybe even favor different types of high nutrient loving plants. Nature has many different species of microscopic plants. Some can live in the snow fields of the artic and some can live in hot springs of western areas. Once introduced into the conditions they - love they thrive.
No.3. The smaller the pond the quicker the whole ecosystem responds to added nutrients and over enrichment. It is a normal natural process. You fertilize it and something will eventually grow and thrive. Once nutrients become accumulated into a pond basin how are they supposed to get out - difficult process.

Dealing with these types of problems is a whole different topic with a numerous methods. Search for unwanted phytoplankton blooms.