Ken,
Thanks for all the input. It's great to have this resource.
As far as where the excess nutrients are coming from, the only source I can see is the decaying leaves in the pond. Over the years the pond was surrounded by brush and trees. We have over the last few months removed about 90% of them. The only runoff that goes into the pond is from my property and there is no source for extra nutrients there. There is a horse pasture next door (100 yds) but there are berms in place.
The pond has few other weeds other than the algae. A little American pond weed and unfortunately a lot of Horsetail.
You mention a three year program. I realize that it's a balancing act and the previous owner let it go too far. I just don't want to start off on a path that is going to be too difficult to recover from if it doesn't work.
A little of topic but worth mentioning is that my pond is the water source for the house. Which is one reason that I am wary of using chemicals. I do have a well on the property but it is very high in hydrogen sulfide, which is very common in this area. It is normal practice around here to basically spray the well water into the pond and allow the gas to escape and then pull water to the house and treat it there. The previous owners never did this but the level of the pond was so low this spring I wanted to see if the pond would hold water up to the overflow.(Thankfully...so far so good.)
