It is important to understand that KOOL KOUNT Assayer (KKA) is a very competent and flexible microbial measurement tool. Occasionally, first time users of the product do not understand the results of KKA when comparing the results previously obtained from often less reliable microbial testers such as agar paddle testers. The purpose of this document is to explain the validity of KKA.

Unlike most microbial testers in its product class, KKA can perform both presence (total) or activity (untreated) measurements. KKA's normal mode, activity measurement, may or may not agree with presence measurements typical of agar pads, paddles and plates testers. Further, KKA supports more important cooling tower species than many agar paddle or pad products such as nitrifiers, fungi and Legionella species. For these reasons, valid scientific cause exists for different readings when comparing KKA results to results from previously used microbial testers . Understand these differences and you can use the additional knowledge given by KKA to gain a competitive edge with your biocide treatment program.

Presence Measurement - The presence measurement is the total number of microbes present at the time of testing. The total presence concentration includes both viable, replicating microbes (active) and near death or incapacitated microbes (inactive).

Activity Measurement - The activity measurement is the number of microbes which are viable and replicating. This measurement is the count of microbes unaffected by the biocide. As the concentration of uninhibited microbes, the "active" microbe count is a good basis for determining when new biocide additions should be made. For example (see graph below), if the presence count by agar paddle is 10⁵ and the activity count by KKA is 10², the microbial counts are not in conflict but accurate. The cooling tower is in control. The difference between the presence and activity measurements in this case represents the count of microbes which have been inhibited by the biocide being used at that biocide's concentration level. Further additions of the same biocide at these low activity levels which do not decrease the activity count could increase the risk of bio-filming as the active or biocide tolerant microbes are apt to be stimulated to increase levels of polysaccharide production.

Testing for Presence - Neutralize the biocide in your water sample. Allow the sample to sit for 15 minutes and then use KOOL KOUNT Assayer as normal. By neutralizing the biocide, dying and incapacitated microbes will recover much like in a plate or paddle test and they will be detected by the KOOL KOUNT Assayer.

Testing for Activity - DO NOT neutralize the water sample. Simply use KOOL KOUNT Assayer as normal. This reading will not necessarily give the same result of the traditional paddle tester but it will give the count of microbes which are not being effected by the biocide treatment program.

Note how the activity measurement changes daily as biocide concentration dissipates while the presence measurement does not change from day 2-5. This information (activity count) can be used to improve your biocide program effectiveness. For more information, ask for our cooling tower "CASE STUDY" Bulletin.

During the recently completed ASTM "Round Robin" field trials for KOOL KOUNT Assayer, a new and exciting advantage to the product (KKA) was discovered. It was universally observed during the trial that one specific cooling tower water sample developed red masses (specs) in the assayer after 6-7 hours. Further analysis revealed that the water contained a high concentration of fungi. The fungi (eukaryotic cells) had ingested the active indicator, reduced it, and turned pink. While KKA was designed to provide bacteria counts (prokaryotic cells), these results suggest that KKA will also provide fungi detection when present at high levels. Even though work to provide a calibrated interpretation of fungi levels as indicated by KKA has not been completed, it is now known that red or pink masses in the KKA are indicators of high enough fungal counts to justify treatment. The red specs represent fungi colonies which are producing polysaccharides and they are looking for surfaces (side walls) to attach themselves to (filming). Fungi specs will be irregular in size and shape. One or two specs in a KKA versus 20 or 30 are a relative indication of concentration level and environmental stress. This product feature would appear to be very important for effective fungi control during periods of high concentration of airborne spores. Because currently available field fungal analyzers (agar paddles) are irrelevantly slow, do not recognize spores and are highly subjective, this new discovery about KKA has significant merit. Immediately KKA users are provided with a speedier (8-10 times faster) method of determining unacceptable fungal levels.