Thanks for all the info on the chara plant - didn't realize that it had that much going for it. It apparently does have a filtering effect on the pond water. I tried spraying liquid Phosphorus on a small area of a pond where the wave action was minimal and which had previously been cleared of Pondweed with Aquathol K.(mainly as a test) . The ponds have a high alkalinity count (65 to 70 ppm) and the bloom appeared about 2.5 to 3 days later.