Let's assume James's dimensions are correct, and that the tank is 6 feet in diameter and 11 feet high (I'll average his "10 to 12 feet"). The radius is therefore 3 feet. The area of the base is therefore 3.14159 (pi) times the square of the radius or 28.27 square feet. Multiplying this by the height gives about 311 cubic feet. Each cubic foot is 7.5 gallons, so the tank would hold about 2,332 gallons. Each cubic foot weighs 62.4 pounds, so the weight would be about 19,406 pounds, or slightly less than 10 tons. I hope I got this right
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