Know your algae before treating or trying to cure it - similar to dealing with a disease or illness. As J.Gray says there are numerous types or species of filamnentous algae each has evolved for different types of growing conditions. Very often filamentous algae grows because unused nutrients are available for its use plus water clarity, temperature, and space conditions favor its growth. Lack of other competition by plants for the available nutrients and space allow filamentous algae to grow "at will" or unrestricted and are "fed" by those available nutrients.
A pond covered across the entire bottom with cattails will likely eliminate severe filamentous algae problems, but that situation is not very practical. Other types of less problematic plants rather than cattails would be a better choices of helping consume excess nutrients.
We are in the infancy of this theory, but adjusting the nitrogen to phosphorus ratio (N:P) to favor phytoplankton growth shading the water and consuming nutrients instead of having filamentous algae be the dominant plant could be a viable solution.
Last edited by Bill Cody; 02/19/13 11:19 AM.
