So here is the aforementioned black tank dump.
Honestly, it wasn’t bad. All of the pipes connected like they were supposed to, therefore we had no big crap explosions or anything that Billy’s nightmares were made of.
Basically in the bus we have three tanks. One is the freshwater tank, which is filled from whatever water hookup is available (spigot at a campsite, hose from a house, etc.) and holds the water that we use throughout the bus. One is the grey water tank, which collects used water from the kitchen sink, bathroom sink, and shower, and the other is appropriately called the black tank, which collects all the contents from the toilet.
You can see the grey tank on the left, and the black on the right – we connected the hose at the bottom of the little T pipe, then lifted the valve for the black. Once that was emptied, we closed the valve and opened the grey, letting it sort of rinse the pipe. After that we disconnected the hose, and then took a shower with straight bleach. Just kidding. The boys were willing to help, Ellie, not so much. But she did take pictures 🙂