Fuel tank cleaning
I had mine cleaned about 6 months ago. I am in San Diego. It cost $600. It is a 70 gal. tank. The cost was high because I had to have a hole cut into the top of the tank, thru which the sludge which had collected at the bottom was cleaned out (hard to do). The fuel was "cleaned" as it was taken out, through two filters I recall, and then "cleaned" again thru filters on the way back in. Since, I had added a chemical each time to keep this from happening again.