to prevent the growth of bacteria in the tank, it should be kept full as often as possible. Condensation causes water to settle to the bottom of the tank, especially when the boat is winterized. An anti-bacterial additive can also be used as a preventive measure.
Read more: https://www.boatsnews.com/story/43567/clogged-diesel-filter-how-to-avoid-running-out-of-fuel-on-your-boat