[Daryles]

I just got done de-winterizing today. Rig was bone dry. I also have an inline water meter.
Flushed the water heater with a Camco rinse wand. Cleaned and put the anode rod in.
I had to sanitize the system so I poured 2 cups of bleach (2 cups for 64 gallons of freshwater to sanitize) in the water hose and connected it to the city water - FILL. Turned "ON" the water heater bypass (don't want the bleach going into the water heater until it's mixed properly). Started filling the tank.
At 42 gallons I turned off the hose and turned on the water pump. I turned OFF the water heater bypass and opened the pressure relief valve to let the air out. Once bleach water started coming out I turned off the relief valve.
I turned the water hose back on and continued filling the freshwater tank. I went inside and opened each faucet to get air out of the pipes until I smelled bleach water, then closed the faucets.
Finally water started coming out the freshwater tank vent. I turned off the water hose.
The water meter read 66 gallons.
So.

50 gallons freshwater
12 Gallons water heater
4 gallons in the pipes.

Normally during a regular freshwater tank refill it overflows at 42 gallons.