@ michiganmudman: The bags are 50 pounds each. I probably have about 25-30 bags tops in the pool. The basic red oxide clay (redart) is what I buy most of because it's cheap at around 17/bag. The fancy dark clay (Barnard slip) is about 50 for the same size bag, and the Kaolin (EPK is name I get) is about 25 I think. hope this helps!