Method of monitoring microbiological deposits

A method for monitoring one or more deposits including microbiological deposits on a surface immersed in an aqueous medium of a process comprising:

• a. providing a QCM that is in contact with an aqueous medium, wherein said QCM has a top side surface contacting the aqueous medium, and a second, bottom side surface isolated from the aqueous medium;
• b. providing a composition that is selective for one or more deposit types comprising microbiological deposits, the composition without the use of an antigen or an antibody, wherein the composition comprises one or more nutrients and/or biocides;
• c. applying said composition to the top side of said QCM surface;
• d. measuring the rate of deposition of said deposits from the aqueous medium onto the top side of said QCM surface;
• and
• e. optionally taking corrective action to change one or more process parameters, or chemistry applied to the process, or a combination thereof, to achieve a desired result in regards to microbiological deposition.