Best method to clean older 5 gal. Diesel cans (plastic)

[ericm979]

If there's algae (very dark red almost black gunk) in them the best thing I have found is dish soap and water followed by blasting the inside with a garden hose. Pressure washing might work too. Drain well and set aside somewhere dry for a few days to finish drying.

Also if there's algae you might not want to run the fuel in your engine as you'll likely get algae in the tractor's fuel tank.