Tim, there are 2 formulations of pond clear, the earliest version used sodium carbonate for the pH buffer-which is fine and safe to use but adds no additional alkalinity per application. The newest formulation does not list the buffering agent on the MSDS sheet yet still says you can mix the product with water and pour. If it was Hydrated lime, mixing with water would not be possible so I can't say what it is.
Generally speaking, to lock up nutrients and sink them, it takes about a minimum of 150lbs of Alum per acre ft of water, sometimes 200lbs.
With that said, I've made 1 application at my pond last year with 550lbs of Alum and 150lbs of hydrated lime to buffer the pH. That application cleared it somewhat but I believe I was slightly light on the Alum rate, so I don't know how a 5 gal bucket can clear much volume.
