Effective biofilm control techniques for clean water systems

25th September 2023

Bacteria in water systems are ubiquitous and diverse. Should a closed system show signs of corrosion and loss of efficiency, biofilm might be the culprit, causing Microbiologically Influenced Corrosion (MIC).

Biofilm is traditionally controlled by maintaining relatively low general bacteria (Total Viable Count) levels. These planktonic bacteria levels have no relationship with the presence biofilm, however – biofilm contains bacteria in the sessile form (surface adhering), which means it would not necessarily be detected in a sample.

Overall, biofilm proliferation in water systems can lead to a myriad of problems, compromising water quality and system efficiency. As a trusted water treatment company, we are well-versed in the control of biofilm formation and combatting resilient bacterial ‘hide-outs’.

In this blog, we’ll explore the importance of biofilm control, discuss various techniques and products available, and highlight how Guardian can help you maintain clean and efficient water systems.

Understanding biofilm and its impact:

Biofilm is a complex community of different competitive and symbiotic microorganisms and chemical gradients that have adhered to surfaces of metal components in heating and cooling systems. When the environmental conditions are optimum, biofilm can proliferate in pipes, effecting the efficient operation of cooling towers, boilers, chillers, plate heat exchangers and heat pumps. In the worst cases, corrosion will occur, predominately in the form of pitting.

Over time, biofilm will affect water flow and reduce heat transfer efficiency. The biofilm colonies can be made up of one or several notable corrosion influencing bacteria in their sessile form, such as Sulphate Reducing Bactria (SRB), Iron Oxidising Bacteria, Denitrifying Bacteria etc.

Benefits of biofilm control:

Effective biofilm control is crucial for operational reasons:

  1. Enhanced water quality: Controlling biofilm proliferation helps maintain good water quality by preventing contamination by potentially corrosion influencing substances and microorganisms.
  2. Improved system efficiency: Clean surfaces promote better heat transfer and operational efficiency in water systems and allow inhibitors to do their job.
  3. Extended equipment lifespan: Controlling the environment in which a biofilm can thrive can prevent corrosion and premature equipment failure.

How to control biofilm from pipes:

For effective biofilm removal from pipes, it is essential to follow a systematic approach:

  1. Assessment: Guardian’s experts conduct a thorough assessment of your water system to identify the risk of biofilm proliferation and the most suitable control technique.
  2. Tailored solutions: Based on the assessment, Guardian customises a biofilm removal plan that aligns with your system’s unique requirements.
  3. Identify biofilm risk: Advise on any operational aspects of the systems that will assist in reducing the risk of a biofilm.
  4. Application: Using advanced techniques and products, Guardian’s team carries out the biofilm removal process efficiently and safely.
  5. Prevention: To prevent future biofilm formation in closed systems, Guardian recommends using real-time, 24/7 condition monitoring to check the parameters that can lead to biofilm, such as changes in pH, dissolved oxygen levels and corrosion rates. The ideal companion to planned preventative maintenance, monitoring in this way will lead to reduced biofilm risk.

Biofilm control techniques:

Guardian Water Treatment employs a range of proven techniques for effective biofilm removal, including:

  1. Mechanical cleaning: Mechanical methods involve physically flushing, scrubbing or brushing the surfaces to dislodge and remove biofilm. This technique is particularly useful for larger pipes and hard-to-reach areas. Thermal vessels are effective bacterial hideouts, and the inspection and cleaning should be a part of any successful planned maintenance.
  2. Chemical cleaning: Utilising safe and targeted chemical agents, this method helps dissolve and break down biofilm. Guardian ensures that only approved and environmentally friendly chemicals are used in this process.
  3. High-pressure water jetting: Water jetting at high pressure can effectively dislodge and flush away biofilm from various surfaces in tanks or thermal storage vessels.
  4. Ultrasonic cleaning: Ultrasonic waves are used to disrupt and remove biofilm, especially in areas with intricate structures or delicate equipment.
  5. Heat treatment: Applying controlled heat to water systems can aid in biofilm control, as some microorganisms are sensitive to elevated temperatures.
  6. Flushing and chemical dosing: Once biofilm has been dislodged, flushing removes contaminated water from the system, with chemical dosing preventing future attacks.
  7. Filtration: Removing potential nutrients such as dead bacteria shells and fine filtration to control general free flow bacteria levels.
  8. Advising on good management of operational systems: Managing seasonal shutdowns without remedial actions, removal of redundant pipe work, correct mothballing and re-commissioning of capital equipment.


Biofilm control is a critical aspect of maintaining clean and efficient water systems. With Guardian Water Treatment’s expertise, advanced techniques, and preventative approach, you can ensure that your water-carrying equipment remains free from biofilm-related challenges.

The most effective way to control the biofilm potential in a closed system in the first instance is good design and operating the systems as designed.

Secondly, simply monitoring the corrosion rate or corrosion indices will give sufficient heads-up information if bacterial counts suggest that MIC is active within the system.

Partner in biofilm prevention

Whether you need biofilm removal in pipes or comprehensive water treatment solutions, Guardian is your reliable partner in safeguarding the integrity and safety of your water systems.

We can offer a yearly suite of sampling to identify any corrosion causing bacteria that may be present. This would supplement and support general total bacteria sampling and thus reduces maintenance sampling for bacteria that are not helpful when assessing the MIC potential.

We can also review the systems operation and inspect for potential ‘hide out’ areas of pipe work that could become a risk for biofilms to be successful.

Choose Guardian Water Treatment for effective biofilm control and exceptional water treatment services. Contact us today to keep your water systems in top condition!