Make life easier and just screw on a water hose nozzle and adjust it to the spray pattern you like. Cheap plactic, "selectable patter" nozzles are only about $3 at Wal-Mart.
Like I said, it is critical that you start in the deepest areas and work your way to the shallows along with speading the spray the Alum in thin even patterns.
The Hy Lime is far less important and can even be broadcast dry over treated areas. It will dissolve quickly and spread evenly throughout the water naturally.
