You should turn it off for about 48 hours. If you've used enough alum to get all the clay, the flocculation will have ceased by then. The floc will then slowly compress itself over time on the bottom. EVERYTHING in the pond will have a sediment layer on it untill the fish dust their house clean.

Best of luck Ryan, and take your time! try to apply the alum for water depth. Deeper water = more alum.