IMO you definitely did not use enough alum for 3/4 ac of turbid water. Do you know the acre feet of water in the pond?? When you did the jar test did you do the math calculation of weight or amount of alum added to the jar for the volume of water tested?

When you add the alum, I would run the aeration until all the alum get well mixed into the entire pond volume, top to bottom. This may take 2-3 hrs after you finish adding all the alum. Then shut off the aerator so all the coagulated precipitate to settle to the bottom. This may take 4-10 days. Then restart aeration. Maybe slowly at first for the beginning 4-6 days. Watch for clarity changes after restarting aeration. Do you have a secchi disk and know how to use it?

aka Pond Doctor & Dr. Perca Read Pond Boss Magazine -
America's Journal of Pond Management