tongue weight

is the listed tongue weight on the pods dry or wet?

Ditto

Subtract the 40# water weight.  On our 177 the FW tank is located behind the axle so in essence you will be subtracting all your water weight off the tongue. 

The full weight of what you put on the tongue does NOT show up as tongue weight. It's a lever, the farther from the ball, the smaller the percentage actually transferred.

Our Pod had dual 6v batteries, dual propane tanks, and an electric jack. WEIGHED, not guessed, tongue weight was 360 ready to camp.

Here is a process to get tongue weight with a standard bath scale: To do this, you'll need a two-by-four cut to a five- or six-foot (1.5- or 1.8-meter) length, two pipes, your bathroom scale, and a brick. Lay one of the pipes across the scale and the other across the brick. Position the scale and the brick so the pipes are exactly three feet apart. Now, lay the two-by-four across the pipes, and find a suitable way to support the tongue of the trailer at the same height as the tow vehicle's hitch ball. Place the tongue (and hitch-height support) on the two-by-four exactly 2 feet (0.6 meters) away from the pipe lying across the scale and 1 foot (0.3 meters) away from the pipe lying across the brick. Read the weight displayed on the scale, and then multiply the weight by three. This is your tongue weight. As posted, you can adjust the weight of the cargo forward or rearward of the trailer axle to reach your target tongue weight. Just watch the scale -- and don't forget to multiply the displayed weight by three.