You must be reading my mind! Just an hour ago I send an email requesting permission from BP Australia to reprint two articles on Diesel fuel that specifically deal with this problem so that I could put them in my cruising dictionary (www.cruiser.co.za/faq.asp
). Here are the links for everybody now so you don't have to wait for bureacrats to figure out whether their permission is going to allow me to makes scads of money, and if so, how they can get some of it. (sorry, that was VERY snide and totally uncalled-for - in this case.)
Diesel Fuel - Fungal Contamination
(this deals specifically with diesel fuel used in boats)
Long Term Storage of Diesel Fuel
(answer - 12 months or longer at 20 degrees C or LOWER, or 6-12 months at temps of 30* C or higher) - and more than just fungi or algae, read article carefully.
Those primary/secondary filters get to be quite expensive if you are using bad fuel.