I had re-posted that from the figure Rex had posted. I think water hardness and pH have a lot to do with what works well. I've used it twice in client ponds based on app rate from TA&M. I did get to talk to a real person at the university to ask if I had misunderstood application rates. As it turns out, I did exactly what they told me to do. The recommendation I got was to wait 2 weeks and proceed with an Alum treatment as I have been doing.
They believed it had something to do with high pH and total hardness. That was the end of the discussion.