Algae in cooling water

Algae growth in cooling water indicates suitable conditions for microbiological expansion, with sufficient nutrients and heat available. Algae spread throughout the system from cooling towers through pipes to heat exchangers, forming biofilm at low-flow points. This biofilm serves as a breeding ground and food source for Legionella and other bacteria.

According to regulations (VDI 2047 part 2), biocide shock dosing should be performed when bacterial counts reach 1000 CFU/100ml, though this can be expensive for larger cooling towers. Rather than treating symptoms, prevention focuses on addressing root causes. Merus technology reduces algae reproduction; algae treated with Merus rings reproduce less quickly and turn brown faster, collecting at the tower sump. With reduced algae populations, biofilm receives less nutriment, weakens gradually, and dissolves. Without biofilm present, Legionella reproduction becomes significantly more difficult.