Blackwater Tank

I relocated the toilet in my travel trailer. It is a 42 gal tank with a sloped bottom. Since the toilet drain is a gravity system, you will need to be sure that your new stool location is within the tank's boundaries (not a simple job when installing from above and locating close to the tank;s sidewalls) or you will need to relocate the tank. I had a 3" pipe for drain. I cut the hole throug the floor with a 4" hole bit and then stepped down to the correct size hole bit to complete the entry hole into the tank. Online retailer "Tank Depot" sells the necessary tank-pipe gaskets that insure a leak-less pipe-to-tank connection. I closed off the original hole with a shorter length of pipe and a screw cover so that I have access to the tank for a future tank cleaning system or insertion of a cleaning wand if there is a problem. I haven't had any issues to date.