Also make sure to seal the vent on your tank, and run a vent line through the floor to the rear of the trailer. Bleach fumes are heavier than air (making a roof vent next to useless), and will cause more corrosion than the occasional spill of liquid. You can also run a fill line with check valve through the floor, and eliminate spills entirely.
Look up Kevin Enderle's posts on Power Wash Community on FB for diagrams. Very simple to do, and will save you from buying a new trailer every few years