True or False: It may be better to collect cooling tower samples into untreated bottles before adding Sodium Thiosulfate.

Collecting cooling tower samples into untreated bottles before adding Sodium Thiosulfate is an approach that allows for the accurate assessment of the water's microbiological profile. Sodium Thiosulfate is used as a dechlorinating agent to neutralize residual chlorine in water samples, which is crucial when assessing for the presence of Legionella or other microorganisms.

If the sample is collected in a treated or pre-additive bottle, the risk of interference from the added chemicals could alter the microbial populations, leading to inaccurate results. Therefore, starting with untreated bottles helps to ensure that the samples reflect the true conditions of the cooling tower water without external influences from additives. This practice is particularly important for obtaining reliable data for Legionella assessment as it minimizes the potential for false negatives or false positives that could occur due to chemical interactions.

This reasoning supports the idea that collecting samples in untreated bottles first is indeed preferable, ensuring a more reliable analysis of the sampled water.