diesel additives

I've always stored with full fuel & never had any of my coach's sit for more than 4-5 months. Been golden for 20+ years! I also never used a biocide but I do now before I put away for winter. Routine service two years ago showed algae in my filter. What I would do is add a biocide now & use the shock dose. It's better to add while filling to help mix but you don't have that option. Also purchase a couple extra fuel filters to carry. If you find you had no algae that's fantastic. If you did you'll also want to continue adding another additive to clean up the dead algae. Below is the Cummins line up but there are others if you prefer.

Cummins products