How much water is generally needed for a bacteriological sample?

For bacteriological sampling, a volume of 100 ml is commonly used as it allows for effective analysis while minimizing potential contamination. This amount provides a sufficient quantity of water to ensure that organisms present can be detected in the sample without being overly diluted.

Choosing 100 ml also aligns with standard procedures that balance practicality and efficiency in laboratory practices. Smaller volumes may not capture the full microbial community present in a larger water source, while larger volumes could be impractical for handling or could lead to unnecessary delays in analysis. Thus, the selection of 100 ml is widely regarded as optimal among water quality professionals.