In this article, we will introduce the three most common culture media and culture methods among all methods of measurement of total colony forming units. Due to difference of media, temperatures, durations or culture methods, we will get different counts of total colony forming units. If the initial culture condition is more similar to the condition of water used during hemodialysis, bacterial culture will better reflect the severity of bacterial contamination of water used for hemodialysis. As a result, this article suggests that we should use low nutrient culture media, such as R2A or TGEA, according to Taiwanese/international examination guidelines of water used for hemodialysis. The use of low nutrient culture media will help slow-growing bacteria and injured bacteria to achieve the best growth condition. In the same time, this article also suggests the bacterial culture should be under the temperature of 17 ~ 23°C, and continues for 168 hours, to enhance colony formation for the bacteria that possibly exist in hemodialysis solution.