This has been a great read. So answer me this, my pond is 3/4 full and its about 1/2 acre average 4ft deepest 8ft, if i put 3 50lb bags of alum in there and it clears up to a decent clarity then the rains come and the water runs off the pasture and down the clay banks its going to get muddy again but the alum will still be in there on the bottom, right? Then when its full I can do it again and and again untill it stays clear and al that alum will stay in my pond. So from then on out every time it gets disturbed from the bottom some alum will be kicked up along with the clay and it will settle back out.Also could you explain to me about the difference in ponds that are mainly filled with "soft rain water" my pond is mostly rain water I dont have much water shed. I know that if I do this now I will need to do it again when full. I just dont know if I should wait or start doing it now. some pics here http://public.fotki.com/tz/clearing-and-pond-p/34-full/