If there is a waterbed bladder that is 30 inches wide x 80 inches long x 9 inches deep?

Question

how many gallons are used and how much does it weigh

Answer 1

This is more like a math question, but I'll give it a try.

Let's see, 30 x 80 x 9 = 21,600 cubic inches.

231 cubic inches of water = 1 US gallon, so that would be about 93.5 gallons.

A gallon of water weighs 8.345 lbs. so that would be about 780.3 lbs.

You may want to double check my math, but that sounds about right.

Note also that waterbeds stretch a lot, so it may be in reality more than the calculated amounts.

Hope that helps.