‘The longer fuel is in storage and the more water is in the tanks, the more the bugs will breed’
I was recently asked specifically to talk about diesel bug at an Inland Waterways Association branch meeting, so it may be a good time to repeat the advice.
Bug is a generic term that covers microbes, moulds, slimes and yeasts found in all diesel fuel. If fuel has a bio-diesel component then this will encourage bug formation. The longer fuel is in storage and the more water is in the tanks, the more the bugs will breed until they eventually start to block filters and pump valves.
Try to buy your fuel from outlets with high throughputs and also take steps to prevent the bug breeding.
Try to minimise the amount of water in the base of the tank, keep it as full as possible during the winter and give consideration to the regular use of a water-removing fuel additive. I drain the bottom of my tank each spring.
If, during servicing, there is any sign of discoloured fuel or slime in the old filters, immediately use a suitable biocide additive – but be prepared for more frequent filter changes.