At first I could not figure out why my camper came with a shower and a toilet. I figured it out after a few years. The shower is for storage and the toilet and black tank is for additional potable water capacity. It just takes a small ladle to dip the water back out through the tiny hole, and some good coordination holding that pedal down while doing it. I used to use a Homer bucket to get the water out at that 3" blade valve under the trailer, and then pour it in the gravity fill, but that would get me some strange stares at the campground.
