In searching algae I find many comments about nutrients that feed the algae and that it is important to control and limit the nutrients. I am not sure what is meant by nutrients and where they come from.

To me it sounds like it would be fertilizer run off or something like that but I do not have that and I have plenty of FA.

My pond is old an in bad health which I am trying to fix. It has been overgrown for years so there is a lot leaf material and muck, which I think is the decaying by product of years of leaves falling in the pond. Is this a source of the nutrients that feed FA?

I also think the pond is probably anaerobic which from what I have read may be because of the leaves and muck - is this right?

I had been thinking about getting some crawfish but I don't want to introduce a species not already there so I am thinking the following:

1) Mechanical removal of the FA mats on the surface.
2) Treat with some Cutrine
3) Introduce aeration
4) Rent a trash pump and suck out some of the leaves and muck
5) Introduce some bacteria
6) Rinse and repeat... :-)

What do you think?