I suggest a treatment of your tank with some Biocide, available at truck stops, marine stores and farm supply stores.

The biocide will kill the bacteria and break them up so they will flow through your filters and burn up.

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[SIGPIC] Diesel loving autocrossing grandpa Architect. 08 Dodge 3/4 ton with Cummins & six speed; I have had about 35 benzes. I have a 39 Studebaker Coupe Express pickup in which I have had installed a 617 turbo and a five speed manual.[SIGPIC]

..I also have a 427 Cobra replica with an aluminum chassis.