That's a bit confusing Gary, because the brochures also say if the fresh water tank(s) is/are full, it adds 300# to the total weight of the trailer.
Now, water weighs 8.3454# per gallon, at 80 deg F, and if you multiply 8.3454 x 36 = 300.4344#, which would imply that the fresh water tank is 30 gals + 6 gals in the hot water tank. Multiplying 8.3454 x 30 = 250.362#, which is 50# lighter. I have never actually measured the water volume in the fresh water tank though, so I have no idea how much water my cold tank holds.
It wouldn't surprise me though to find that the cold tank was only 24 gals. I know it's easy to go through it while camping.
- Jack