Kirk, read through this thread. http://www.pondboss.com/forums/ubbthreads.php?ubb=showflat&Number=124005#Post124005

There has been some debate whether it has to be mixed or not, but results from a pre-mix are MUCH better. Pour the slurry into a prop wash or use a sprayer to apply it. Consider the pond's depth when applying (ie more slurry in deeper areas) to maintain even concentration.