Fishntx85, I'll be in Texas applying alum to a couple ponds, but judging by your dimensions, I'd suggest 1000 pounds of Alum. Like has been said, adding Alum will clear the muddy water, but with all that bare clay, it will be just as bad again the next decent rain.
If you get near Houston, Kelly Duffie at Helena has Alum, or send me a PM and I can arrange for you to pick it up in SA at one of my suppliers.
