Calculating the volume of a cylinder (aerator)

I have had many customers ask how to calculate the total weight of our aerators when filled with water. Here is an example with our 4' plug aerator:

Radius x Radius x Pi x Length

8 x 8 x 3.14159 x 48 = 9651 cubic inches

9651 cubic inches = 41.78 gallons

1 gallon of water = 8.33 pounds

41.78 gallons of water = 348 pounds

Rounding just a little, that water adds 350 lbs.

Added to the units weight, that's a total of 465 lbs.

that's roughly 66 lbs. per plug, which is pretty good.