I will be using plumbers tape on all the threaded junctions and most likely some sort of silicone seal or rtv on anything that's not threaded.
I got an RV water pump that is 12 v and has a pressure switch so it kicks on when the spigot opens.
The stock bumper has 4 drain holes on the bottom that I am plugging with stainless bolts that I will be able to remove to drain the bumper at the end of the season.
Couldn't tell from the pics. How do you fill it?