Update: I located a gypsum mine in Oklahoma. Hoskins Gypsum. Although the water jar tests had previously indicated that it would take a whopping 96 TONS of gypsum to clear my 11 acre pond, but that seemed excessive to me.
I had an 18-wheeler hauling an end-dump trailer make the trek to Oklahoma and pick up all it could haul. Purchased 20.5 tons of their 6-8" gypsum rock at $12 per ton at the mine. Transportation costs were the most expensive part.
We dumped the gypsum rock in piles along two spots on the bank. I had read on two different sites (including Bob Lusk's Pond Boss website) that gypsum rock would take longer to show the effect, approximately 4-6 weeks.
Long story, short: the gypsum rock was extremely effective. I went from maybe 8 inches of pretty red/muddy visibility and being unable to see the fish hit the fish food, to now about 20 inches of visibility and all of the red clay color gone from the pond, and am able to see the fish come up and hit the food. I am very glad I went this route.
