I am currently working for a farmer. His farm manager is experiencing tractor diesel filter clogging on a regular basis. It is claimed that the new bio-diesel mix is to blame. Apparently the bio-diesel mix with normal diesel attracts moisture and that causes growth of algae and bacteria in the diesel which blocks fuel filters. Diesel polishing can clean contaminated diesel fuel. This process filters out the dirt, rust and growths using filters of increasing fineness in stages of filtration. So, if you have a standby generator that is diesel powered it may be advisable to get the diesel fuel cleaned regularly, tanks cleaned and a "biocide" added to stop growth in the fuel, to maintain reliability.
https://www.bbc.co.uk/news/business-25321913
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