Wolfman -
We usually have the best results going with 6 to 8 lbs per square foot. Take the surface square footage of your pond and add 30% for the bottom contour increase. This is the square footage you want to base your total poundage off of.
Bulk bentonite is available in Fort Worth, but a small pond like yours I'd recommend just getting a few pallets of 50# bags. Each pallet is 3000# and is about $250 to $275 per ton.
Good luck!
Trent
