My pond has had a cloudy film on the surface since about May. If there is a prevailing wind, it all collects in the downwind part of the pond.
Otherwise, it is spread across the whole pond.

I'm assuming this is some sort of algae. What can be done about it? Will some sort of carp control this?

TB - What color is the "cloudy film"? Light green, dark green, other? Does it have any visable structures (seen w/o a lens or scope)? It could be a form of phytoplankton or blue-green algae. Your post doesn't reference a local, which would be of great help since posts from all over North America show up on this board. My visits to the board are infrequent these days, so email me if you're seeking a rapid response. Send a pic of the stuff if you have it. KD

TB,
There has been a cloudy, dusty looking film on my pond since about May, also. It goes away for a few days after a rain and then shows up again.
In my case, I am pretty sure that it is tree pollen. Could this be what you have?

Larry

Larry,

That is possible. My pond is surrounded by pine trees. Is pollen a problem in the summer? I thought that was a spring problem.

TB

TB,
I am far from an expert on tree pollen, but I believe that pine tree pollen is produced in the spring. That probably isn't your problem if it is still around.


Larry

TB, one way to rule out the pine pollen is to lay something out close to the pond where the yellow pollen will collect. Make sure that what ever color it is will give you a good contrast to the yellow pollen. I believe while most pollen is produced in spring, it can still produce in the summer. My pond gets this film on calm days, it could also be the result of the air quality if you are close to a city.