Chandler1, your PH can change dramatically thoughout the day, but 9 is pretty high. I would opt for a much more accurate test to be sure. Some organic floc may float, but suspended clay will sink rapidly...with the rather high alum rate I suggested, your pond should be very clear in less than a day and unless runoff flows though the pond, new erosion will sink as well.
I would get the eroded spots covered with some decorative rip rap if it were my pond in such a beautiful setting!
