What I took away from that thread is that the Alum was a temporary fix. New rain and the clay it creates, simply clouds the water again.
Once you get the banks and other incoming water sources stabilized, the alum will capture much of the remaining suspended particles.
I have an 18 month old pond that I've had problems stabilizing with vegetation on its rather steep and wet banks. I have a couple of settling ponds that feed this pond, and several settling ponds below it that feed my main pond. The settling incoming and outgoing settling ponds have extremely clear water.
I just put down a bunch more seed and straw in the last couple of weeks on the banks of this pond. I'm going to wait at least until next season before I put in alum, or a commercial solution based on alum.
