Diesel Bug

Stored diesel fuel faces a significant risk of diesel bug infestation over time, primarily due to a combination of fuel contamination and moisture. This issue is commonly observed among boat owners who store their vessels with fuel in the tank during winter months. Regardless of tank size, diesel fuel in storage can undergo condensation, creating an ideal breeding ground for diesel bug growth.


The term 'diesel bug' encompasses various types of bacteria and fungi that thrive in fuel. Whether you're involved in fleet management or marine vessel operation, especially during prolonged mooring, understand how to recognise, prevent or treat diesel bug is crucial to guard against its consequences, such as clogged filters and engine fuel shortages. In the event of an infestation, filters may become coated with dark brown to blackish slime.

Diesel Bug Testing

Diesel Bug dipslides
Buy Now

Diesel Bug Treatment

Diesel Bug treatment
Buy Now

The FA-ST Dip Slides makes the determination of these microbial counts fast, easy and is unique in that both measurements can be made simultaneously. The FA-ST bacteria & fungi test kits contain dip slides that are coated with an agar culture medium. Each test kit is complete and ready to use straight away. No special equipment or training is necessary.


Each side of the dip slide is coated with a different medium, one side being selective for fungi and the other for bacteria. Almost all aerobic bacteria will grow on the side designated for those organisms. Their growth will be in the form of red dots, also known as colonies, on the surface of the agar. The dip slide is compared to a chart in order to get a quantitative interpretation of the results.


Most fungi (yeast and mould) that contaminate aqueous industrial systems will grow on these dip slides. On the side designated for fungi, growth of yeast and mould will generally appear as cottony, filamentous structures. The reacted dip slide is compared to a colour chart from which an estimated fungal count can be made.

Diesel Bug Treatment is a broad spectrum. The biocide has been formulated to prevent or eradicate the microbial contamination of fuel from yeast, mould and bacteria commonly known as diesel bug.


If an infestation of diesel bug has entered your system then it must be treated with a biocide to remove the contamination from your tank. By just flushing the tank the infection will remain and once new fuel is added to bug will grow again.

FA-ST offer a range of Hydra Biocide to treat any diesel bug infestations that enter your tank. Hydra Biocide will:


  • Ensure that any stored/remaining fuel in the fuel tanks remain protected against microbes for long periods.
  • Immediately rids all contamination and prevents the regeneration of microbes.
  • Safe to use as it is non-flammable, non-toxic, non-corrosive. Totally combustible in fuel mixture.
  • Hydra FuelPlus Biocide is soluble in both fuel and water phases for better and efficient killing.
Share by: