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If you have a cooling tower in your premises, then it is in your best interests to keep it clean. While this can sometimes be a very difficult and time consuming job - its long term benefits are well worth it.

Picture of an office cooling towerWhat's Causing It?

The slime build up in your cooling tower is actually a substance called biofilm, which is a product of the microorganisms that live in your boiler. Scientists like to call this gooey coating 'Extracellular Polymeric Substances' - but if you've ever had first-hand experience of it you might just call it slime!

The microorganisms that have made their home in your boiler or cooling tower create this biofilm slime as a way or protecting themselves. They live within or underneath this protective sheath and thrive, so the more slime you have, the more microorganisms have been living in your cooling tower rent free. But be careful when you go in to clean it - some of these creatures can be quite dangerous. For example, certain bacteria that reduce sulfites can cause some significant corrosion in your systems. Legionella is another common bacteria found in the average cooling tower, and the biofilm this produces is the leading cause of Legionnaires disease - a very dangerous form of pneumonia.

So What Is It Costing Me?

Now, while having biofilm in your cooling tower isn't causing you to pay out lots of money - you are still losing money and putting a lot of other things at risk as well. For example:

Your cooling tower will not be operating as efficiently. Biofilm is an incredible insulator, and if it gets into your cooling towers it will affect the way they work, and you will be using more power and more money to keep the towers working properly. To put it into perspective - a thin layer of biofilm just 1/5 of a millimetre thick will reduce your efficiency by over 10%!


You are putting yourself and your employees, and even the public, at risk. If you have an outbreak of biofilm in your system, it is a predicator to some much more dangerous things. You could, for example, be harbouring a strain of water borne pathogen, holding any number of bacteria and viruses including Legionnaires' disease. If your premises is close enough to be spraying mist over a local populated area, you are liable for any damages and illnesses stemming from that mist.

Finally - you are risking a lot of damage to your equipment, which could cost you a small fortune in repairs or replacements. Those sulfite reducing or iron depositing bacteria that can cause biofilm to form can also destroy steel - the very substance your cooling towers are made of. In severe cases, these bacteria can eat away at 1 inch thick steel tubing in as little as 18 months. Can you justify replacing your entire cooling system just because of some slime?


If you need any advice or help with biofilm in your cooling towers, please get in touch to find out more.  Aster Maintenance on 01252 844 055 or send us an enquiry.