FOPCOINC. ( Fuel Oil Polishing COmpany) is the leader in the fuel polishing industry bringing back the old school way of polishing diesel. Utilizing a Harvard filtration system FOPCO can bring results down to 1 micron. FOPCO also can remove bacterial and fungal growth with our exclusive enzyme saving costs for our customers. FOPCO also can pull 98% of water out of the tank with our polymer compound and giving them the peace of mind to leave the job up to us.