This thread was started upon discovering a black gooey slime in the diesel tank which may or may not have anything to do with the use of Biobor JF. I forgot who started the thread but would like to obtain some more info on the situation from anyone else who has encountered the black slime.... I am the one who found black goo in my Racor filter after a year and a half of inactivity. George of Scaramouche1, Lake Ontario, Canada