If you read the fine print, they refer to changing the pH of the top 1/2" of soil in that acre. I don't know of any fish that live in only the top 1/2" of water in a pond.......
When it comes to ponds, especially a 9 ac pond, I've learned that there is no such thing as a fast acting magic bullet to make changes besides Rotenone and copious amounts of Hydrated Lime.
