bob, do you think it might just be fa? my experience with fa was mats that broke free from the bottom and floated up. liquid cutrine always did the trick. i have noticed it kicked back my bloom a little like you mentioned.

i forgot to mention in the other post i have going about diquat, but my pond seemed to bloom as soon as the pondweed and chara was knocked back. within just a few days.. might just be coincidence

Scott Hanners