I just happened to stumble across some guys that were cleaning the tanks of a nearby trawler. "I've got about 30 gallons of left over highly polished diesel, you want it?"

Um, yeah.

They were happy to leave it in those little pony barrels, emptied and ready for pickup the next day.. Call some guys near you. I'll bet you can work something out.

I have reason to believe my own tank is getting yucky. Ah well.